THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

LOS  ANGELES 

GIFT  OF 


Mrs.  Clifford  B.  Walker 


HANDBOOK 


OF 


OPHTHALMOLOGY. 


BY 

PROF.   C.   SCHWEIGGEE, 

OF    THE    UNIVERSITY    OF    BERLIN. 


TRANSLATED   FROM   THE   THIRD   GERMAN  EDITION 

BY 

PORTER  FARLEY,  M.D., 

ROCHESTER,  NEW  YORK. 


WITH  DIAGRAMS  AND    OTHER   ILLUSTRATIONS. 


PHILADELPHIA: 

J.    B.   LIPPINCOTT   &   CO. 

1878. 


Copyright,  1878,  by  J.  B.  Lippincott  &   Co. 


Biomedicd 
Libraiy 

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100 
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TRANSLATOR'S    PREFACE. 


In  presenting  his  work  to  the  profession,  the  translator  wishes 
to  acknowledge  the  assistance  received  during  its  preparation 
from  his  friend  Dr.  Charles  E.  Rider,  of  Rochester,  N.Y. 

During  the  work  of  translation  his  advice  on  all  doubtful 
points  was  freely  sought  and  as  freely  given.  While  the  book 
has  been  passing  through  the  press,  he  has,  at  the  expense  of 
great  labor  and  care,  assisted  in  the  reading  and  revision  of  tlie 
entire  proof. 

EocHESTER,  N.Y.,  Feb.  15,  1878. 


635919 


CONTENTS. 


PART    FIRST. 

Anomalies  of  Refraction  and  Accommodation.  Condition  of  refraction.  Em- 
metropia.  Far  point.  Near  point.  Limits  of  range  of  accommodation.  Rel- 
ative range  of  accommodation.  Mechanism  of  accommodation.  Optical  deter- 
mination of  range  of  accommodation.  Senile  changes  in  eye.  Presbyopia. 
Correction  by  convex  lenses.     Acuteness  of  vision       .....       11  30 

Myopia.  Its  degree, — anatomical  and  ophthalmoscopical  changes,  causes,  and 
course.  Functional  anomalies  and  complications.  Position  of  absolute  and 
relative  range  of  accommodation.  Insufficiency  of  internal  recti.  Relative 
divergence.  Amblyopia  complicating  extreme  myopia.  Myodesopia.  Cloud- 
iness of  vitreous.  Posterior  polar  cataract.  Choroiditis  near  equator  and 
macula  lutea.  Enlargement  of  Mariotte's  spot.  Scleral  staphyloma  near  pos- 
terior pole.  Metamorphopsia.  Detachment  of  retina.  Use  of  eyes  in  myopia. 
Correction  by  concave  lenses.     Symptoms  of  irritation        ....       31-51 

Hypermetropia,  absolute,  relative,  facultative.  Range  of  accommodation  and  its 
relative  extent.  Latent  tension  of  accommodation.  Accommodative  asthenopia. 
Causes  and  diagnosis.     Correction  by  convex  lenses    .....       52-62 

Astigmatism,  irregular  and  regular.  Physiological  meridional  asymmetry.  Prin- 
cipal meridian.  Focal  lines.  Focal  range.  Abnormal  meridional  asymmetry. 
Impairment  of  vision.  Accommodative  asthenopia  in  hypermetropic  astigma- 
tism. Diagnosis.  Degree  of  astigmatism.  Lens  participates  in  the  asymme- 
try. Directions  of  principal  meridians.  Correction  by  cylindrical  and  sphero- 
cylindrical lenses.     Stokes'  lenses  . 63-73 

Difference  op  Refraction.     Anisometropia         ......       74-76 

Paralysis  of  Accommodation.  Differs  from  presbyopia.  Micropia.  Paresis  of 
accommodation  a  symptom  of  oculo-motorius  paralysis.  Paralysis  of  pupillary 
branches  alone.  Connection  with  facial  paralysis.  Paresis  of  accommodation 
after  diphtheritis  faucium.  Traumatic  mydriasis  and  paresis  of  accommoda- 
tion               76-82 

Spasm  of  Accommodation.  Apparent  myopia.  Calabar  myosis.  Asthenopia 
from  spasm  of  ciliary  muscle.     Nervous  asthenopia.     Myosis     .         .         .       83-86 

Monocular  Polyopia  and  Diplopia 86 

Spectacles.  Spherical  lenses.  Concave,  convex,  and  cylindrical  lenses.  Pris- 
matic spectacles.     Stenopaic  apparatus.     Protective  spectacles    .         .         .       87-94 

Ophthalmoscope.  Upright  image  in  emmetropia,  in  myopia,  in  hypermetropia. 
Inverted  image.  Size  of  ophthalmoscopic  image.  Binocular  ophthalmoscope. 
Bering's  experiment.     Examination  by  daylight  .....     95-115 

Ophthalmoscopic  Diagnosis  of  Anomalies  of  Refraction,  of  astigmatism    .  116-119 


6  CONTENTS. 

Ophthalmometer.  Corneal  curvature  in  emmetropia,  myopia,  and  hypermetro- 
pia.     Angle  cc.     Apparent  strabismus  divergens  and  convergens         .         .  119-125 

Diseases  of  the  Ocular  Muscles.  Movements  of  the  eyes,  and  laws  of  diplopia. 
Centre  of  revolution.  Extent  of  ocular  movements.  Laws  of  innervation. 
Overcoming  prisms.  Physiological  diplopia.  Double  images  united  by 
prisms 126-134 

Paralysis  of  Abducens.  Diminished  motion.  Imperfect  associated  movement. 
Secondary  deviation  of  healthy  eye.  Paralytic  squint.  Behavior  of  double 
images.  Limit  between  region  of  single  vision  and  diplopia.  Masked  diplo- 
pia. Treatment.  Use  of  prismatic  spectacles.  Exercise  of  paralyzed  muscle. 
Result  in  strabismus  convergens  ........     134—141 

Paralysis  of  Oculo-Motorius,  complete  and  partial.  Dizziness  from  false  pro- 
jection of  visual  field.  Etiology.  Treatment.  Indications  for  tenotomy  of 
rectus  superior  and  inferior  .........     141-145 

Paralysis  of  Trochlearis.  Action  of  rectus  inferior.  Behavior  of  double 
images.     Differential  diagnosis  from  paralysis  of  rectus  inferior        .         .     145-147 

Spasm  of  Ocular  Muscles 148 

Strabismus.     Distinction  between  paralytic  and  typical  or  concomitant  squint    .  149 

Strabismus  Convergens.  Its  connection  with  hypermetropia,  amblyopia,  and 
loss  of  accommodation.  Elasticity  of  muscles.  Reflex  impulses.  Stationary 
monolateral  squint.  Invariability  of  squinting  angle  upon  change  of  fixation, 
and  exceptions  to  the  rule.  Alternating  strabismus  convergens.  Periodic 
squint.  Linear  measure  of  squint.  Simultaneous  upward  or  downward  squint. 
Binocular  vision  with  strabismus.  Suppression  of  retinal  images  in  squinting 
eye.  Proof  that  squinting  eye  participates  in  vision.  Provocation  of  double 
images.  Use  of  stereoscope.  Vision  in  squinting  eye.  Amblyopia  congenita. 
Separate  exercise.  Spontaneous  disappearance  of  squint.  Therapeutic  use  of 
convex  lenses       ............     149-165 

Strabismus  Divergens.  Preponderance  of  externi.  Unilateral  blindness.  Uni- 
lateral myopia.     Relative  divergence  in  myopia  .....     165-168 

Muscular  Asthenopia  and  Dynamic  Squint.  Insufficiency  of  recti  interni. 
Condition  of  refraction  in  reference  to  diagnosis.  Use  of  prismatic  spectacles. 
Indications  for  tenotomy  of  recti  externi    .......     168-173 

Squinting  Upward  and  Downward      ........     173, 174 

Operation  for  Strabismus.  Simple  tenotomy.  Mechanical  eflfect  of  operation. 
Operation  divided  between  both  eyes.  Influence  upon  acuteness  of  vision  and 
binocular  vision.  Correction  of  the  hypermetropia  by  lenses.  Dissimilarity 
of  squinting  angle  after  unilateral  operation.  Twitching  fixation  movement. 
Bringing  forward  ocular  muscle 174-187 

Nystagmus 187, 188 

PART    SECOND. 

Diseases  of  the  Orbit.  Inflammation  of  fat  and  connective  tissue.  Abscess. 
Purulent  periostitis.  Danger  of  blindness  from  ulceration  of  cornea,  from 
neuritis,  from  detachment  of  retina,  or  from  purulent  choroiditis.  Course  and 
treatment.  Caries  and  necrosis  of  orbital  walls.  Exophthalmus  from  morbus 
Basedowii,  from  obstruction  of  circulation.  Pulsating  exophthalmus.  Tumors 
of  orbit.  Hemorrhage.  Fractures  of  orbital  walls.  Emphysema  of  orbit. 
Foreign  bodies.     Exophthalmometer 191-202 

Diseases  of  Lachrymal  Organs.  Inflammation  of  lachrymal  gland  (dacryo- 
adenitis).     Fistula   of  gland.     Dacryops.     Tumors  and  extirpation  of  gland. 


CONTENTS.  7 

Congenital  anomalies  of  piincta  lacrymalia.  Foreign  bodies  and  cryptogams 
in  canaliculi.  Ectropion  and  occlusion  of  canaliculi.  Dacryocystitis.  Stric- 
tures of  canaliculi.  Bowman's  probes.  Cutting  stricture.  Cauterization  of 
lachrymal  sac.     Lachrymal  fistula.     Polypi  of  canaliculi  ....     203-217 

Diseases  of  Eyelids.  Blepharitis.  Phtheiriasis  of  cilia  and  eyebrows.  Horde- 
olum. Abnormities  of  tarsal  glands.  Chalazion.  Herpes  zoster  frontalis. 
Eczema,  erysipelas,  and  abscess  of  lids.  Syphilitic  ulceration  of  lids  and  con- 
junctiva. Lupus.  Epithelioma.  Telangiectasia.  Cystic  tumors  of  lids.  Ephi- 
drosis.  Seborrhoea.  Chromhidrosis.  Xanthelasma.  Blepharospasm.  Ptosis. 
Paralysis  of  orbicular  muscle.  Lagophthalmus.  Ectropion.  Entropion. 
Blepharophimosis.  Distichiasis  congenita.  Epicanthus.  Coloboma  of  upper 
lid.     Symblepharon.     Blepharoplastic  operations       .....     218-251 

Diseases  of  Conjunctiva.  Hyperaemia.  Conjunctivitis,  simple  or  catarrhal. 
Chronic  conjunctivitis.  Atropine  conjunctivitis.  Blennorrhcea  of  conjunctiva. 
Blennorrhoeal  corneal  affections.  Rules  for  cauterization.  Chronic  blennor- 
rhoeal  processes.  Diphtheritic  conjunctivitis.  Swelling  of  conjunctival  folli- 
cles. Trachoma.  Ophthalmia  militaris,  granulosa,  etc.  Hemorrhage  beneath 
the  conjunctiva.  Serous  swelling.  Lupus.  Pemphigus.  Foreign  bodies. 
Burns.     Pterygium.     Pinguecula.     Phlyctenular  conjunctivitis         .         .     252-290 

Diseases  of  the  Cornea.  Examination  by  focal  illumination.  Keratitis  phlyc- 
taenulosa,  parenchymatosa,  punctata.  Hypopion.  Keratitis.  Corneal  abscess. 
Ulcus  corneae  serpens.  Neuro-paralytic  keratitis.  Corneal  ulceration  with 
interstitial  encephalitis.  Corneal  ulcers.  Corneal  opacities.  Irregular  astig- 
matism. Staphyloma.  Corneal  fistula.  Cysts  on  cornea.  Keratoconus. 
Wounds  of  cornea.     Tumors  of  cornea.     Arcus  senilis        ....     291-.325 

Diseases  of  the  Sclera.  Scleritis  and  episcleritis,  simple  and  complicated. 
Scleral  staphyloma       ...........     326-331 

Diseases  of  the  Iris.  Iritis  idiopathica.  Relapsing  iritis.  Total  adhesion  of 
pupillary  margin.  Irido-choroiditis.  Corelysis.  Iritis  syphilitica,  gummosa. 
Hydro-meningitis.  Secondary  iritis.  Irido-cyclitis.  Sympathetic  disease. 
Enucleatio  bulbi.  Membrana  pupillaris  perseverans.  Irideremia.  Disap- 
pearance of  iris  by  sinking.     Coloboma  iridis.     Tumors  of  iris  .         .     332-355 

Diseases  of  the  Lens.  Senile  changes.  Soft  cortical  cataract.  Cataracta  seni- 
lis, congenita,  diabetica.  Complicated  cataract.  Examination  of  vision.  Par- 
tial opacity  of  lens.  Cataracta  incipiens,  punctata,  striata.  Lamellar  cataract. 
Cataracta  centralis  anterior,  pyramidalis,  centralis,  posterior.  Calcification  of 
lens.  Cataract  operation.  Linear  extraction.  Iridectomy  in  flap  operation. 
Peripheral  linear  incision.  Discision.  Cataracta  traumatica.  Capsular  and 
secondary  cataract.     Luxation  of  lens.     Aphakia      .....     356-392 

Diseases  of  the  Vitreous  Body.  Liquefaction  and  detachment.  Myodesopia. 
Opacities.  Hyalitis.  Cholesterin  in  vitreous.  Recurring  hemorrhages  into 
vitreous.  Development  of  vessels  in  vitreous.  Arteria  hyaloidea  persistens. 
Cysticercus 393-400 

PART    THIRD. 

Normal  Fundus  of  Eye.  Optic  disc.  Lamina  cribrosa.  Differences  in  level 
about  disc.  Physiological  excavation.  Ophthalmoscopic  diagnosis  of  differ- 
ences of  level.  Central  vessels  of  retina.  Adventitial  layer  visible.  Venous 
pulsation.  Arterial  pulsation.  Retina  visible.  Its  physiological  opacity  and 
reflex.  Macula  lutea.  Fovea  centralis.  Choroid,  differences  in  its  pigmenta- 
tion.    Albinismus.     Intervascular  spaces  of  choroid  ....     403-417 


8  CONTENTS. 

Diseases  of  Choroid.  Hyperaemia.  Cyclitis,  idiopathic  and  as  sequel  of  recur- 
ring fever.  Purulent  choroiditis.  Puerperal  choroiditis.  Embolism.  .  Irido- 
choroiditis  in  cerebro-sjjinal  meningitis.  Acute  irido-choroiditis.  Calcification 
and  ossification.  Acute  choroiditis,  disseminated,  syphilitic.  Detachment. 
Rupture.     Miliary  tubercle.     Choroidal  sarcoma.     Coloboma  of  choroid  .     418-438 

Diseases  of  Retina  and  Optic  Nerve.  Medullary  nerve-sheaths.  Hyp^rsemia  of 
retina.  Detachment  of  retina.  Pigmentation  of  retina.  Hemorrhage  in  retina. 
Retinitis.  Ophthalmoscopic  indications.  Disturbances  of  vision.  Different 
forms  of  retinitis.  Anatomical  changes.  Neuro-retinitis.  Choked  disc.  Con- 
nection with  intracranial  diseases.  Retrobulbar  neuritis.  Ischaemia  retinse. 
Anatomical  changes  in  neuritis  and  neuro-retinitis.  Embolism  of  central  artery 
of  retina.     Atrophic  degeneration  of  optic  nerve.     Glioma  of  retina         .     439-500 

Glaucoma.  Glaucoma  simplex.  Pressure  excavation.  DiS'erential  diagnosis  of 
optic-nerve  excavations.  Determining  increased  tension  by  touch.  Tonometer. 
Atrophy  of  nerve  fibres  in  consequence  of  excavation.  Contraction  of  visual 
field  and  diminution  of  vision.  Inflammatory  glaucoma.  Symptoms  of  intra- 
ocular pressure.  Clouding  of  refracting  media.  Arterial  pulsation.  Seeing 
colors  of  spectrum.  Prodromal  stage.  Glaucoma  ehronicum,  acutum,  and 
fulminans.  Glaucomatous  degeneration  and  atrophy  of  eyeball  with  detach- 
ment of  retina.  Etiology.  Secondary,  glaucoma.  Iridectomy  in  glaucoma. 
Cystoid  cicatrization.     Cure  by  iridectomy 501-523 

Essential  Phthisis  Bulbi 524,525 

Amblyopia  AND  Amaurosis.  Examination  of  visual  field.  Amblyopia  congenita. 
Color-blindness.  Hemeralopia.  Anesthesia  and  hyperajsthesia  of  retina. 
Amblyopia  with  no  cause  to  be  seen  ophthalmoscopically.  Amblyojjia  pota- 
toria  and  saturnina.  Scotoma  centrale.  Progressive  atrophy  of  optic  nerve. 
Hemiopic  defect  in  visual  field.  Amaurosis  from  intracranial  and  cerebral 
causes.  Uraemic  amaurosis.  Amaurosis  following  haematemesis.  Amaurosis 
simulata 526-546 


PART   FIRST. 

ANOMALIES  OF  KEFRACTION  AND  ACCOMMODATION. 
—SPECTACLES,  OPHTHALMOSCOPE,  AND  OPHTHAL- 
MOMETER.—ANOMALIES    OF   THE    OCULAR    MUSCLES. 


I. 

ANOMALIES  OF  REFRACTION  AND  ACCOMMODATION. 


Thanks  to  the  lucid  treatment  of  this  subject  by  Donders, 
the  Anomalies  of  Refraction  and  Accommodation  have  become 
one  of  the  clearest  and  most  complete  chapters  of  ophthalmology. 
Even  the  first  step  was  decisive.  The  sharp  distinction  which 
Donders  made  between  Refraction  and  Accommodation  was  suffi- 
cient to  banish  all  obscurity.  By  refraction  we  understand  that 
optical  adjustment  of  the  eye  which  de})ends  upon  its  anatomical 
Structure ;  the  accommodation  includes  those  changes  of  the  op- 
tical adjustment  which  are  effected  by  the  ciliary  muscle.  Hence 
we  can  say  that  the  refraction  is  that  optical  condition  of  the  eye 
which  we  have  when  the  ciliary  muscle  is  wholly  relaxed. 

The  anatomical  components  which  determine  the  optical  struc- 
ture of  the  eye  are  as  follows:  (1)  the  curved  surfaces  of  the  diop- 
tric apparatus, — i.e.,  the  surface  of  the  cornea,  the  surfaces  of 
the  lens,  together  with  the  distance  between  these  surfaces;  (2) 
the  refractive  index  of  thfe  transparent  media, — i.e.,  of  the  cornea, 
aqueous  humor,  lens,  and  vitreous  body ;  and  (3)  the  length  of 
the  axis  of  the  eye. 

The  great  number  of  these  components,  and  their  liability  to 
variations,  naturally  cause  different  conditions  of  refraction  in 
different  individuals.  Donders,  however,  easily  succeeded  in 
arranging  the  possibilities,  since  he  started  out  with  the  behavior 
of  the  eye  toward  rays  of  light  which  fall  parallel  upon  the  cor- 
nea ;  for  such  rays  after  refraction  in  the  eye  must  be  focused 
either  upon  the  sensitive  layer  of  the  retina  or  before  or  behind  it. 

Hence  there  may  be  three  different  conditions  of  refraction, 
perfect  rest  of  accommodation — that  is,  total  relaxation  of  the 
ciliary  muscle — being  always  assumed. 

When  rays  of  light  which  proceed  from  a  point  lying  at  an 
infinite  distance,  and  whicli  are  therefore  practically  parallel,  fall 

11 


12  REFRACTION. 

upon  the  cornea,  and  are  focused  upon  the  retina,  we  have  emme- 
tropia;  if  focused  in  front  of  the  retina,  we  have  myopia;  if  behind 
the  retina, — that  is  to  say,  if  the  rays  after  their  refraction  in  the 
dioptric  apparatus  converge  toward  a  point  lying  behind  tlie  retina, 
— we  have  hypermetropia. 

Perhaps  it  will  contribute  to  the  elucidation  of  this  subject  if 
we  call  attention  to  the  fact  that  the  eye  considered  as  an  optical 
instrument  is  constructed  like  a  camera  obscura.  In  fact,  it  is  just 
as  important  with  the  camera  obscura  of  the  photographer  as 
with  the  eye  that  the  optical  image  of  the  object  be  thrown  with 
perfect  distinctness  upon  the  sensitive  plate.  Now,  under  what 
conditions  will  this  requirement  be  satisfied  ? 

Let  us  first  examine  the  camera  obscura,  which  in  its  simplest 
form  consists  merely  of  a  convex  lens  and  of  a  ground-glass  plate, 
upon  which  the  optical  image  is  received.  This  image  depends 
upon  the  fact  tliat  the  rays  of  light  which  proceed  from  each 
separate  point  of  the  object  are  brought  again  to  a  point.  We 
may  therefore  consider  both  the  object  and  the  image  as  com- 
posed of  an  infinite  number  of  points,  and  what  is  true  of  one 
object-point  and  of  its  corresponding  image-point  is  true  of  all. 

If  the  position  of  the  object-point — that  is,  its  distance  from  a 
convex  lens — be  given,  the  position  of  the  image-point  depends 
upon  the  focal  length  of  the  lens,  or  in  other  words,  upon  the 
distance  at  which  parallel  rays  are  brought  together.  The  less 
this  distance,  the  greater  is  the  refractive  power  of  the  lens. 
Focal  length  and  refractive  power  are  therefore  in  inverse  pro- 
portion. If  one  lens  has,  for  instance,  a  focal  length  of  1  inch, 
while  another  lens  has  one  of  2  inches,  and  a  third  one  of  3 
inches,  then  the  refractive  power  of  these  lenses  is  as  1 :  J :  J.  We 
therefore  express  the  optical  value  of  a  lens  by  a  fraction  whose 
numerator  is  1  and  whose  denominator  is  the  focal  length  of  the 
lens.  The  optical  value  of  a  lens  of  ten  inches  focal  length  is 
thus  expressed  by  ■^.  This  is  ten  times  less  than  that  of  a  lens 
of  one  inch  focal  length.  In  expressing  the  power  of  lenses  any 
other  unit  of  measure  may  of  course  be  taken  as  well  as  the  inch. 

If  /  in  Fig.  1  be  the  image-point  belonging  to  an  object-point 
infinitely  distant,  the  point  of  union  for  parallel  rays — that  is, 
the  principal  focus  of  the  convex  lens — lies  at/.  The  optical  value 
of  the  lens  would  therefore  be  expressed  by  j. 


REFRACTION.  13 

From  the  above  it  follows  that  a  camera  obscura,  in  order  to 
form  images  of  distant  objects,  must  be  so  constructed  that  the 
focus  of  the  convex  lens  falls  exactly  upon  the  ground-glass  plate; 
and  conversely  a  camera  obscura  whose  screen  lies  in  the  focus  of 
the  convex  lens  can  give  sharp  images  of  only  such  objects  as  lie 
practically  at  an  infinite  distance  from  the  lens.  Precisely  these 
optical  conditions  exist  in  the  emmetropic  eye ;  when  its  accom- 
modation is  wholly  relaxed  the  retina  lies  exactly  in  the  principal 
focus  of  the  dioptric  apparatus. 

Fig.  1. 


If  the  object-point  is  not  at  an  infinite  distance  the  image- 
point  will  not  coincide  with  the  principal  focus,  but  its  position 
will  be  determined,  as  has  already  been  mentioned,  by  the  dis- 
tance of  the  object-point  and  by  the  focal  length  of  the  convex 
lens. 

It  is  evident  from  Fig.  1  that  rays  of  light  which  proceed  from 
/are  so  refracted  in  the  lens  that  they  will  be  focused  at  an  infi- 
nite distance  beyond  it,  or  what  is  the  same  thing,  and  is  expressed 
by  the  dotted  lines,  they  take  a  direction  as  if  they  had  proceeded 
from  a  point  at  an  infinite  distance  in  front  of  the  lens. 

The  farther  the  object-point  is  removed  from  the  lens  the  nearer 
the  image-point  approaches  it,  until  finally,  upon  infinite  removal 
of  the  object-point,  tlie  image-point  coincides  with  the  principal 
focus.  Thus  rays  of  light  which  diverge  from  a  point  more  dis- 
tant than  the  principal  focus,  become  convergent  after  passing 
through  the  lens  and  intersect  each  other  in  an  image-point  whose 
distance  is  likewise  greater  than  that  of  the  focus. 

Let/,  in  Fig  2,  be  the  focus  of  the  convex  lens,  a  the  luminous 
point,  and  oc  the  image-point,  then  an  inverted,  diminished  image 
of  an  object  lying  at  a  will  be  formed  at  oc,  while  if  the  rays 
diverge  from  oc  their  union  takes  place  in  a,  and  an  inverted, 
enlarged  image  of  oc  would  there  be  formed.  The  distances  of 
a  and   oc  are  thus  conjugate  focal  distances,  each  of  which,  just 


14 


ANOMALIES    OF    EEFEICTION. 


as  in  the  case  of  the  pinncipal  focal  distance,  is  expressed  by  a  frac- 
tion whose  numerator  is  one,  and  whose  denominator  is  the  distance 
of  the  points  a  and  oc  respectively  from  the  centre  of  the  lens.  The 
optical  significance  of  the  object-point  is  expressed  by  \,  that  of 
the  image-point  by  ^.  We  obtain  in  this  way  three  optical  values, 
whose  relation  to  each  other  is  expressed  by  the  formula^  +  h  =  7- 
By  this  formula,  when  two  values  are  given,  we  obtain  the  third. 

Fig.  2. 


If  we  have,  for  instance,  a  camera  obscura  with  a  lens  of  4 
inches  focal  length,  while  the  screen  lies  not  at  the  princi})al  focus 
of  the  lens,  but  at  5  inches  from  the  centre  of  the  lens,  we  have 
given  the  values  of/ — i.e.,  the  principal  focal  length — and  oc, — 
i.e.,  the  distance  at  which  the  image  is  to  be  thrown.  The  for- 
mula 5^  +  ^  ^7  becomes  ^  -[-  3-  ^  i?  that  is,  ^  =  -^.  The  object 
must  therefore  be  at  a  distance  of  20  inches  in  order  to  cast  its 
image  on  the  screen,  or  in  other  words,  the  camera  obscura  is 
adjusted  for  a  distance  of  20  inches. 

So  it  is  with  the  eye  which  is  adjusted  for  a  determinate  finite 
distance,  either  by  the  action  of  its  accommodation  or  by  its  optical 
structure.     The  latter  is  the  case  in  the  short-sighted  eye. 

The  third  possibility  is,  that  the  screen  of  the  camera  obscura 
may  lie  within  the  focal  distance  of  the  lens.  For  what  distance 
is  the  instrument  now  adjusted  ?  where  must  the  object  be  placed 
to  cast  its  image  on  the  screen  ? 

We  have  seen  that  objects  at  a  finite  distance  cast  their  images 
beyond  the  principal  focus.  The  further  the  object  is  removed 
the  nearer  its  image  approaches  the  principal  focus,  and  finally, 
when  the  object  is  at  an  infinite  distance,  its  image  is  formed  ex- 
actly at  the  principal  focus  of  the  lens.  An  object  cannot  be  at 
a  greater  than  an  infinite  distance;  therefore  a  camera  obscura, 
whose  screen  lies  within  the  focal  distance,  can  exhibit  no  distinct 
pictures.    Since  this  condition  actually  exists  in  the  hypermetropic 


ANOMALIES    OF   REFE ACTION.  15 

eye,  we  must  examine  it  more  closely,  and  apply  to  it  the  formula 
for  conjugate  foci. 

Fig.  3.  •   ' 


If,  for  instance,  the  convex  lens  in  Fig.  3  have  a  focal  length  of 
3  inches,  then  7=^;  and  if  the  screen  be  2  inches  from  the  lens, 
then  1=^,  and  we  have  from  the  formula 

a  ^  CC J 

■^  +  ^=1-,  or  ^^|-  — 1-==  — \.  The  negative  sign  shows 
that  ravs  of  light  which  proceed  from  a,  after  refraction  in  the 
convex  lens,  diverge  as  if  they  had  proceeded  from  oc ;  cc  is  the 
image-point  of  a;  but  since  the  rays  do  not  actually  intersect  at 
oc,  but  only  diverge  as  if  they  had  proceeded  from  it,  the  image 
at  oc  is  called  a  virtual  image. 

It  follows  further  that  when  we  can  give  to  rays  proceeding 
from  any  given  point  a  direction  such  that  they  converge  toward 
the  point  oc,  they  will  after  refraction  in  the  convex  lens  form  an 
optical  image  at  the  point  a.  Under  these  conditions  a  distinct 
image  will  be  formed  in  spite  of  the  faulty  construction  of  the 
camera  obscura ;  these  conditions  must  be  fulfilled  in  the  case  of 
the  hyperrnetropic  eye. 

EMMETKOPIA. 

According  to  the  foregoing  the  optical  construction  of  the  em- 
metropic eye  is  such  that  with  absolute  relaxation  of  accommoda- 
tion it  is  adjusted  for  far-distant  objects,  and  throws  distinct  retinal 
images  of  them.  The  ability  to  see  near  objects  distinctly  depends 
upon  the  accommodation. 

The  limits  of  accommodation  are  called  respectively  the  far  and 
the  near  point.  The  position  of  the  far  point  depends  upon  the 
condition  of  refraction.  It  is  the  most  distant  luminous  point 
whose  rays  can  still  be  united  in  an  image  upon  the  retina.  As- 
suming the  accommodation  to  be  relaxed,  the  far  point  of  the  em- 
metropic eye  lies  at  an  infinite  distance,  since  light  which  proceeds 


16  RANGE   OF    ACCOMMODATION. 

from  an  infinitely  distant  point  falls  upon  the  cornea  in  parallel 
rays.  Every  contraction  of  the  muscle  of  accommodation  causes 
the  eye  to  be  adjusted  upon  some  nearer  point.  The  nearest  point 
upon  which,  with  the  full  power  of  accommodation,  the  eye  can  be 
adjusted  is  called  the  near  point. 

Donders  has  shown  that  a  distinction  is  to  be  made  between 
an  absolute  and  a  binocular  near  point.  The  binocular  near  point 
is  the  nearest  point  upon  which  the  accommodation,  with  simul- 
taneous convergence  of  the  visual  axes, — that  is,  with  binocular 
vision, — can  be  directed.  The  absolute  near  point  shows  the  maxi- 
mum power  of  accommodation.  But  this  greatest  possible  action 
of  accommodation  by  which  the  eye  is  adjusted  for  the  absolute 
near  point  can  be  accomplished  only  with  a  relatively  too  strong 
convergence  of  the  visual  axes, — that  is,  with  monocular  fixation. 

These  relations  existing  between  the  convergence  of  the  visual 
axes  and  the  action  of  accommodation  were  first  fully  appreciated 
by  Donders,  and  by  him  explained.  For  the  emmetropic  eye,  he 
showed  that  in  general  the  accommodation  is  adjusted  for  that 
point  in  which  the  visual  axes  intersect  each  other;  and  con- 
versely, in  ordinary  use  under  normal  conditions,  the  visual  axes 
converge  toward  the  point  for  which  the  eye  as  an  optical  in- 
strument is  adjusted.  Nevertheless  there  does  not  exist,  as  was 
formerly  thought,  a  constant  relation  between  the  convergence  of 
the  visual  axes  and  the  degree  of  accommodation.  With  one  and 
the  same  degree  of  accommodation,  there  may  be  a  greater  or  less 
convergence  of  the  visual  axes;  and  conversely,  with  an  unchanged 
angle  of  convergence,  the  degree  of  accommodation  can  be  either 
increased  or  diminished.  We  call  this  space  through  which  the 
accommodation  can  be  effected  without  change  in  the  direction  of 
the  visual  axes  the  relative  range  of  accommodation.  With  an 
unchanged  angle  of  convergence  of  the  visual  axes,  the  accommo- 
dation can  adjust  the  eye  for  the  relative  near  point,  and  relax  it 
for  the  relative  far  point. 

Donders  has  not  only  given  the  proof  of  the  existence  of  rela- 
tive accommodation,  but  has  also  accurately  determined  the  posi- 
tion of  the  relative  range  of  accommodation,  and  of  the  relative 
near  and  far  points  for  every  given  convergence  of  the  visual  axes. 

With  the  help  of  prisms  we  are  able,  with  unchanged  tension 
of  accommodation,  to  alter  the  convergence  of  the  visual  axes. 


RELATIVE   RANGE   OF   ACCOMMODATION. 


17 


If  in  Fig.  4  both  eyes  are  fixed  upon  and  see  distinctly  the 
point  a,  a  distinct  retinal  image  will  be  formed  in  both  eyes  upon 


Fig.  4. 


7^^ 


the  macula  lutea  at  m.  Now,  if  we  place  before  the  eyes  prisms 
with  their  refracting  angles  turned  outward,  the  rays  proceeding 
from  a  will  be  refracted  towards  m',  and  the  point  a  will  be  seen 
double.  Binocular  single  vision  will,  however,  be  soon  re-estab- 
lished by  a  lateral  turning  of  the  cornea,  the  macula  lutea  being 
moved  from  m  to  m'.  The  deviation  caused  by  the  prisms  will 
be  balanced  by  a  compensating  deviation  of  the  visual  axes,  and 
it  is  easy  to  determine  within  what  limits  this  is  possible.  Con- 
versely, by  the  use  of  prisms  with  their  bases  turned  outward,  the 
visual  axes  may  be  caused  to  intersect  at  a  point  lying  nearer  to 
the  eye  than  a,  while  the  accommodation  remains  adjusted  for 
that  point. 

The  results  appear  even  more  striking  in  the  method  usually 
employed  by  Donders,  which  determines  the  limits  of  accommoda- 
tion, while  the  convergence  of  the  visual  axes  remains  unchanged. 

If,  for  instance,  the  object-point  a  in  Fig.  5  is  at  a  distance 

Fig.  5. 


of  12  inches  from  the  eyes,  it  can  be  determined,  while  the 
visual  angle  remains  the  same,  with  what  concave  and  convex 


18  RELATIVE    RANGE    OF    ACCOMMODATION. 

lenses  the  object  may  still  be  distinctly  seen.  If,  for  instance, 
concave  12  is  the  strongest  concave  glass  with  which  binocular 
vision  at  a  distance  of  12  inches  is  still  possible,  it  can  easily 
be  calculated  upon  what  distance  the  accommodation  must  be 
adjusted.  We  employ  again  the  formula  ^  -|-  «=  ±7^  in  which 
a  expresses  the  distance  of  the  luminous  point,  oc  the  distance  of 
the  image,  and  /  the  focal  distance  of  the  concave  or  convex  lens. 
The  value  of  /  is  negative  when  the  focal  distance  is  a  virtual 
one,  as  in  the  case  of  concave  glasses.  Upon  our  supposition  that 
a=12and/=12,  the  formula^ -|-^=  —  jbecomes  ■^-\-^=z  —  ^, 
or  ^= — ^.  The  virtual  image  of  a  lies  at  oc,  6  inches  from  the 
lens, — that  is,  after  their  refraction  in  the  concave  lens  the  rays 
diverge  as  if  they  had  proceeded  from  the  point  oc,  6  inches  in 
front  of  the  lens.  The  accommodation  must  be  adjusted  for  this 
distance  in  order  to  see  distinctly  the  image  at  oc,  while  the  visual 
axes  still  intersect  at  the  point  a.  That  is  to  say,  if  in  our  experi- 
ment the  visual  axes  converge  toward  a  point  12  inches  distant, 
and  — 1^  is  the  strongest  concave  lens  with  which  the  fixation- 
object  can  still  be  distinctly  seen,  it  follows  that  with  the  same 
convergence  of  the  visual  axes  the  accommodation  can  still  be 
adjusted  on  a  much  nearer  point.  We  find  for  this  case  the  rela- 
tive near  point  to  lie  6  inches  in  front  of  the  concave  lens ;  or 
supposing  the  distance  between  the  lens  and  the  optical  centre  of 
the  eye  to  be  J  inch,  the  relative  near  point  lies  6|  inches  distant 
from  the  latter. 

We  can  determine  in  the  same  manner  and  with  the  same  de- 
gree of  convergence  the  strongest  convex  glass  with  which  the 
point  a  can  still  be  distinctly  seen.  In  this  case  the  accommoda- 
tion must,  of  course,  be  relaxed  and  adjusted  for  rays  of  less  di- 
vergence, or  no  distinct  retinal  image  can  be  formed.  If  we  find 
that  while  maintaining  the  convergence  of  the  visual  axes  upon 
a  distance  of  12  inches,  convex  16  is  the  strongest  convex  lens 
with  wdiich  the  fixed  point  can  still  be  distinctly  seen,  we  can,  by 
the  help  of  the  same  formula,  calculate  the  distance  of  the  point 
upon  which,  during  the  experiment,  the  accommodation  must  be 
adjusted.  The  formula  i  +  i=J-  becomes  iV  +  i=i^  oi'  h= 
—  ^;  that  is,  the  virtual  image-point  of  the  fixed  point  a  lies  48 
inches  from  the  convex  lens,  or  the  rays  of  light  proceeding  from 
a  diverge  after  their  refraction  by  the  convex  lens  as  if  they  had 


RELATIVE   RANGE   OF   ACCOMMODATION.  19 

proceeded  from  a  point  48  inches  on  the  other  side.  In  order  to 
see  a  distinct  and  single  image  of  the  point  a,  the  eyes  must  have 
adjusted  themselves  to  such  diverging  rays  without  changing  the 
convergence  of  their  visual  axes.  We  find,  then,  in  this  case, 
with  the  visual  axes  converging  upon  a  point  12  inches  distant, 
a  relative  near  point  6  inches  and  a  relative  far  point  48  inches 
from  the  eye.  Now,  since  the  ordinary  adjustment  of  accommo- 
dation is  upon  the  point  of  intersection  of  the  visual  axes,  the 
range  of  relative  accommodation  is  divided  into  two  parts, — the 
one  within,  the  other  beyond,  that  point  of  intersection.  That 
part  of  the  relative  range  of  accommodation  which  lies  between 
the  fixation-point  and  the  relative  far  point  is  called  the  nega- 
tive part,  because,  under  ordinary  circumstances,  it  is  already  used 
in  accommodating  upon  the  binocular  fixation-point.  The  other 
part,  extending  from  the  point  of  intersection  of  the  visual  axes 
to  the  relative  near  point,  is  called  the  positive  part  of  the  rela- 
tive range  of  accommodation,  because,  with  the  given  degree  of 
accommodation,  it  is  not  yet  brought  into  use.  It  represents  the 
unemployed  power  of  accommodation.  The  results  of  a  com- 
plete series  of  experiments  made  by  Donders  upon  this  subject 
may  be  stated  as  follows : 

(1)  With  parallel  visual  axes  the  emmetropic  eye  is  adjusted 
upon  its  far  point.  Its  accommodation  is  fully  relaxed.  There 
can  be  no  further  relaxation,  but  there  can  be  tension  of  the  ac- 
commodation. All  emmetropes  having  a  good  range  of  accom- 
modation can  see  distinctly  at  a  distance  through  concave  glasses. 
In  such  cases,  in  spite  of  the  jjarallelism  of  the  visual  axes,  the 
accommodation  must  be  adjusted  upon  the  negative  focal  points 
of  the  concave  lenses.  Youthful  individuals  with  a  normal 
range  of  accommodation  have,  with  parallel  visual  axes,  an  at- 
tainable relative  near  point  at  about  12  inches  from  the  eye. 
With  parallel  visual  axes,  the  relative  range  of  accommodation 
is  wholly  positive ;  that  is,  a  stronger  tension  but  no  further  relax- 
ation is  possible. 

(2)  With  convergence  for  the  binocular  near  point  no  further 
tension,  but  only  a  relaxation  of  the  accommodation,  is  possible  ; 
that  is,  the  relative  range  of  accommodation  is  wholly  negative. 

(3)  With  a  degree  of  convergence  for  intermediate  points,  say 
at  from  8  to  24  inches,  as  in  ordinary  work,  the  positive  part  of 


20 


EELATIVE   RANGE   OF    ACCOMMODATION. 


tlie  relative  range  of  accommodation  is  greater  than  the  negative 
part;  that  is,  with  this  degree  of  convergence  only  the  smaller 
part  of  the  whole  available  accommodation  is  employed. 

Bonders  has  presented  these  results  diagrammatically.  The 
principle  of  this  diagrammatic  representation  is,  that  the  distance 
between  two  horizontal  lines  represents  a  definite  result  of  accom- 
modation, which  is  assumed  as  the  unit  of  measure.  As  this  unit, 
^  is  chosen, — that  is,  a  result  of  accommodation  equivalent  to  the 
action  of  a  convex  lens  of  24  inches  focal  distance.  We  begin  now, 
in  Fig.  6,  with  the  lowest  line,  marked  go,  which  represents  the  eyes 

Fig.  6. 


2A 

2f 

3 

34 


44 
6 


12 
24 


/ 

/ 

1 

k/ 

/ 

/ 

.  D 

P^ 

— 

> 

P^ 

>^ 

^ 

7 

^f. 

^ 

>^ 

s 

V 

/ 

^ 

x 

/ 

/ 

y 

y 

y 

Y 

/ 

/' 

y 

y 

A 

^ 

r 

0°       11°2F    22°50^    34°32^    4G°38^    59°20'    72°50^ 


as  adjusted  for  parallel  rays.  The  second  horizontal  line,  marked 
24,  represents  an  increase  of  accommodation  by  2^,  or  the  adjust- 
ment of  the  eyes  for  a  distance  of  24  inches.  The  third  horizon- 
tal line,  marked  12,  represents  an  increase  of  accommodation  by 
twice  -^ ;  the  third  line,  marked  8,  by  three  times  -^ ;  and  so  on. 
The  diagonal  line,  K  K',  represents  the  convergence  of  the  visual 
axes.  The  numbers  in  the  column  on  the  left  express  in  inches 
the  distance  of  the  object.  The  numbers  below  the  diagram 
express  the  angle  of  convergence.  The  distance  between  the  eyes 
is  assumed  to  be  64  millimetres. 

The  position  of  the  relative  near  point  for  every  given  angle 


CHANGES    DUEING    ACCOMMODATION.  21 

of  convergence  is  shown  by  the  line  p^  p^  p,  and  the  position  of 
the  corresponding  far  point  by  the  line  r  r\  The  points  marked 
on  these  lines  were  found  by  direct  experiment. 

The  diagram  shows  that  the  eye,  whose  relative  accommodation 
it  illustrates  with  parallel  visual  axes,  has  its  relative  near  point 
at  a  distance  of  11  inches:  with  an  angle  of  convergence  of 
22°  50'  the  relative  range  of  accommodation  lies  between  a  dis- 
tance of  12  inches  and  about  4.5  inches  from  the  eye.  The 
binocular  near  point  lies  at  p^,  where  the  near-point  line  inter- 
sects the  diagonal  K  K' .  If  the  convergence  of  the  visual  axes 
increases  still  more,  for  instance,  to  46°  38',  the  line^^  jo  remains 
below  the  diagonal  K  K' ;  that  is,  the  tension  of  accommodation 
remains  behind  the  point  of  convergence  of  the  visual  axes ;  if 
this  point  is  3  inches  from  the  eye,  the  accommodation  is  adjusted 
upon  a  point  3.8  inches  distant.  The  absolute  near  point  p  lies 
somewhat  nearer,  at  3.7  inches.  It  can,  however,  be  reached  only 
with  an  angle  of  convergence  of  about  70°,  when  the  visual  axes 
will  intersect  at  a  distance  of  about  2  inches.  At  this  maximal 
tension  the  range  of  accommodation  ends ;  the  lines  p^  p^,  and 
r  r\  end  here  in  one  and  the  same  point. 

The  changes  which  can  be  observed  in  the  eye  during  accom- 
modation are  the  following : 

(1)  The  pupil  contracts  in  accommodation  for  near  objects;  it 
dilates  for  distant  vision. 

(2)  The  margin  of  the  iris  and  the  centre  of  the  anterior  sur- 
face of  the  lens  move  forward  in  accommodating  for  near  objects ; 
simultaneously  the  peripheral  part  of  the  iris  sinks  back,  as  must 
necessarily  be  the  case,  since  the  volume  of  the  aqueous  humor 
remains  unchanged. 

(3)  The  anterior  surface  of  the  lens  becomes  more  curved  in 
near,  and  flattens  again  in  distant,  vision.  This  phenomenon, 
evidently  the  most  important  connected  with  accommodation,  may 
be  directly  observed  by  studying  the  images  reflected  from  the 
anterior  and  posterior  surfaces  of  the  lens.  In  accommodating  for 
near  objects  the  image  reflected  from  the  anterior  surface  of  the 
lens  becomes  smaller,  a  proof  that  the  surface  becomes  more 
curved ;  its  position,  too,  is  changed,  which  is  explained  by  the 
moving  forward  of  the  reflecting  surface. 

(4)  The  image  reflected  from  the  posterior  surface  of  the  lens 


22  OBSERVATIONS   ON   ACCOMMODATION. 

"  also  diminishes  in  accommodating  for  near  objects,  from  which  it 
may  be  concluded  that  during  this  act  that  surface  also  becomes 
more  curved ;  a  simultaneous  change  in  the  position  of  this  surface 
does  not  seem  to  occur.*  Hensen  and  Volckers  found,  on  the 
contrary,  in  the  case  of  dogs,  that  the  posterior  surface  of  the  lens 
moved  backward. 

Observations  in  cases  of  iridectomy  and  of  albinos  with  trans- 
parent iridesf  have  shown  beyond  doubt  that  there  always  exists 
between  the  ciliary  processes  and  the  equator  of  the  lens  a  free 
space,  in  which  the  zonula  is  stretched.  It  is  certain  that  the 
ciliary  muscle  in  contracting  does  not  compress  the  equator  of  the 
lens.  The  phenomena  to  be  observed  after  iridectomy,  in  the 
region  of  the  ciliary  processes,  the  zonula,  and  the  equator  of  the 
lens,  have  been  thoroughly  investigated  by  Coccius.|  He  estab- 
lished the  fact  that  in  accommodating  for  near  objects  the  points 
of  the  ciliary  processes  move  so  far  forward  toward  the  iris  that 
the  processes  themselves  form  an  acute  angle  with  the  axis  of  the 
eye.  The  circle  formed  by  the  ciliary  processes  becomes  smaller. 
Coccius  saw  simultaneously  a  swelling  of  the  ciliary  processes 
and,  in  agreement  with  Becker,  a  widening  of  the  zonular  space ; 
according  to  Coccius,  also,  the  movement  of  the  margin  of  the 
lens  toward  its  centre  during  accommodation  may  be  directly 
observed. 

Hensen  and  Volckers§  demonstrated  in  the  case  of  dogs  a  for- 
ward movement  of  the  choroidea,  simultaneous  with  the  contrac- 
tion of  the  ciliary  muscle.  Adamiuk||  confirmed  this,  but  does 
not  think  it  true  of  man,  whose  ciliary  muscle  has  a  different 
structure  from  that  of  the  dog.  From  the  accommodation  phos- 
phenes,  described  by  himself,  Czermak^  argues  that  there  is  a 
tension  of  the  retina  during  accommodation. 

At  all  events,  the  processes  to  be  observed  within  the  lens  play 
the  most  important  r6le  in  accommodation,  and   there  is  every 

*  Helmholtz,  Physiologische  Optik,  §  12. 
f  Becker,  Wiener  medicinische  Jahrbiicher,  1863  u.  1864. 
+  Der  Mechanismus  der  Accommodation,  Leipzig,  1868. 
g  Hensen  und  Vdlokers  iiber  den  Mechanismus  der  Accommodation,  Kiel, 
1868. 

II  Centralblatt  f.  d.  med.  Wissensch.,  1870,  No.  19. 
^  Archiv  fiir  Ophth.,  vii.  1,  147. 


PRINCIPLES   OF    ACCOMMODATION.  23 

reason  to  believe  that  they  fully  explain  all  the  changes  of  optical 
adjustment.  It  only  remains  to  show  more  exactly  how  the 
changes  in  the  lens  are  caused. 

We  start  from  the  assumption  that  with  perfect  relaxation  of 
accommodation  the  eye  is  adjusted  for  its  far  point,  and  that  with 
each  effort  of  accommodation  it  is  adjusted  for  some  less  distant 
point.  The  simple  suspension  of  accommodation  causes  a  return 
to  the  optical  adjustment  for  the  far  point.  The  truth  of  this  sup- 
position is  established  by  the  fact  that  the  eye  may  be  adjusted  for 
its  far  point  artificially,  by  the  use  of  atropine,  or  pathologically, 
by  the  paralysis  of  accommodation. 

The  phenomenon  of  accommodation  is  reduced  accordingly  to 
an  antagonism  between  the  elastic  strength  of  the  lens  on  the  one. 
side  and  the  zonula  on  the  other,  which  is  excited  by  the  action 
of  the  ciliary  muscle.  The  lens  from  its  elasticity  has  a  tendency 
to  approach  a  spherical  shape ;  Helmholtz,*  who  first  announced 
this  fact,  also  found  that  with  absolute  relaxation  of  accommoda- 
tion for  distant  vision,  the  thickness  of  the  lens  is  less  than  it  is 
after  death. 

The  zonula,  which  is  stretched  between  the  ciliary  processes  and 
the  equator  of  the  lens  and  is  attached  to  both,  tends  by  reason 
of  its  elasticity  to  flatten  the  lens.  So  soon  as  the  zonula  is  re- 
laxed the  lens  will  follow  its  own  elastic  tendency  and  will  assume 
a  greater  convexity. 

It  may  with  the  greatest  probability  be  assumed  that  both  the 
radiating  and  the  circular  fibres  of  the  ciliary  muscle  act  simul- 
taneously to  relax  the  zonula.  The  elasticity  of  the  lens  then 
comes  in  play,  and  the  above-described  changes  in  its  form  occur; 
upon  the  cessation  of  muscular  contraction  the  elastic  tension  of 
the  zonula  acquires  the  ascendency,  and  then  occurs  that  flattening 
of  the  lens  which  corresponds  to  the  condition  of  relaxed  accom- 
modation. 

OPTICAL   DETEEMINATION    OF    THE    KANGE   OF   ACCOMMO- 
DATION. 

It  is  advantageous  in  practice  to  possess  a  uniform  standard  of 
measure  for  the  power  of  accommodation,  in  order  to  compare  the 

*  Physiol.  Optik,  pag.  110. 


24  RANGE  OF   ACCOMMODATION. 

results  of  examinations  in  diiferent  individuals,  or  in  the  same 
individual  under  diiferent  circumstances.  Donders  provided  this 
standard  in  a  very  simple  way  by  comparing  the  result  of  accom- 
modation to  the  optical  value  of  a  convex  lens,  which,  if  placed 
before  the  relaxed  eye,  would  have  accomplished  the  same  as  the 
accommodation  does. 

Let  the  lens  X,  in  Fig.  7,  be  such  that  parallel  rays  striking  its 
surface  are  focused  at  /.  A  screen  at  /  would  show  distinct  pic- 
tures of  distant  objects,  just  as  a  landscape  camera  obscura  does. 

'  Fig.  7. 


If  now  the  instrument  be  adjusted  for  some  nearer  point  upon  the 
axis,  say  at  p,  then,  according  to  the  rule,  the  distance  between  L 
and  /  would  be  increased ;  if,  however,  this  distance  cannot  be 
changed,  there  is  still  a  means  by  which  a  distinct  image  of  jj  can 
be  cast  at  f  •  for  this  purpose  it  is  only  necessary  to  combine  with 
the  lens  L  an  auxiliary  meniscus,  L',  which  has  such  a  focal  length 
that  rays  proceeding  from  p,  after  their  refraction  in  L',  become 
parallel ;  they  then  fall  parallel  upon  X,  and,  according  to  the 
original  supposition,  are  focused  at  /;  now  if,  for  instance,  the 
distance  from  the  point  p  to  L'  is  4  inches,  then  the  convex  me- 
niscus must  evidently  have  a  focal  length  of  4  inches ;  its  optical 
value  would  be  expressed  by  +  \.  The  same  principles  can  be 
applied  to  the  eye.  If  before  an  emmetropic  eye  with  relaxed 
accommodation  we  place  a  convex  meniscus  of  +  \,  the  eye  is 
thus  adjusted  for  a  distance  equal  to  the  focal  length  of  tliis  lens, 
that  is,  4  inches.  If  the  near  point  of  an  emmetropic  eye  is  4 
inches  distant,  then  the  accommodation  does  for  this  eye  just  what 
was  done  by  the  convex  meniscus  for  the  relaxed  eye.  If  we 
represent  the  accommodation  by  the  letter  A,  we  have  as  the 
measure  of  the  accommodation  of  an  eye  whose  far  point  is  at  an 
infinite  distance,  and  whose  near  point  is  at  4  inches,  the  expres- 
sion x=5.  The  optical  value  of  the  accommodation  is  thus  best 
expressed  by  the  principal  focal  distance  of  that  convex  lens 
which,  added  to  the  condition  of  refraction  in  the  eye,  would  com- 


RANGE    OF    ACCOMMODATION.  25 

plete  an  apparatus  adjusted  for  tlie  nearest  point  upon  which  the 
eye  could  have  been  adjusted  by  its  own  physiological  power. 

The  near  point  ^9  corresponds  always  to  the  optical  adjustment 
of  the  eye  when  to  its  anatomical  condition  of  refraction  (deter- 
mined by  the  position  of  the  far  point  r)  the  result  of  accommo- 
dation is  added.  Expressed  in  an  optical  formula  we  have  tH"  i 
=  j;, — that  is,  refraction  plus  accommodation  gives  the  near  point. 
An  immediate  deduction  from  this  is  the  expression  ^=j  —  t, — 
that  is,  when  we  know  the  positions  of  the  far  and  near  points 
we  can  calculate  the  range  of  accommodation.  The  value  which 
we  obtain  assumes  the  form  of  a  fraction  wdiose  numerator  is  1 
and  whose  denominator  expresses  in  inches  the  principal  focal 
length  of  that  convex  lens  which  placed  in  front  of  the  relaxed 
eye  would  have  accomplished  the  same  as  the  accommodation. 

The  same  method  of  mathematical  expression  is  employed  for 
the  relative  range  of  accommodation,  which  is  generally  denoted 
by  A'. 

We  found,  for  example  (page  IS),  with  a  convergence  upon  a 
point  12  inches  distant,  that  the  relative  far  point  lay  at  48 
inches,  and  the  relative  near  point  at  6  inches ;  from  this  we  can 
calculate  the  value  of  the  relative  range  of  accommodation,  x'  = 
1  —  -lg=-^.  The  negative  part  of  the  relative  range  of  accom- 
modation is  in  this  case  -^q,  the  positive  yj- 

PEESBYOPIA. 

Having  thus  obtained  a  common  measure  for  the  range  of  ac- 
commodation in  diiferent  individuals,  Donders  further  showed 
that  the  extent  of  the  range  of  accommodation  depends  upon  the 
age  of  the  individual.  With  the  increase  of  years  the  near  point 
moves  gradually  from  the  eye,  and  the  range  of  accommodation 
is  thereby  reduced.  Two  possibilities  suggested  themselves  by 
which  to  explain  this  phenomenon :  either  the  power  of  the  mus- 
cle of  accommodation  must  weaken,  or  there  must  be  changes  in 
the  elasticity  of  the  lens.  The  circumstance  that  the  range  of  ac- 
commodation is  already  noticeably  diminished  at  a  time  when  the 
strength  of  all  other  parts  of  the  muscular  system  is  unimpaired 
must  banish  the  idea  of  a  premature  loss  of  power  in  the  muscle 
of  accommodation ;  on  the  other  hand,  however,  there  are  all- 
sufficient  proofs  of  changes  in  the  lens  dependent  upon  age. 

3 


26  PRESBYOPIA. 

It  is  known  that  tlie  lens  becomes  harder  with  age.  From  the 
investigations  of  F.  J.  v.  Becker,*  this  hardening  begins  at  a  very- 
early  age,  affecting  first  the  nucleus  of  the  lens  and  spreading  to 
the  periphery.  At  -a  later  age  this  hardening  may  be  plainly 
recognized  by  the  stronger  reflection  of  light  observable  upon 
focal  illumination  of  the  lens.  It  is  fair  to  assume  that  with  the 
change  in  the  index  of  refraction  there  occurs  also  a  change  in 
the  elasticity  of  the  lens,  so  that  it  gradually  loses  the  power  to 
respond  to  the  contraction  of  the  ciliary  muscle  by  increasing  the 
convexity  of  its  curved  surfaces. 

The  gradual  withdrawal  of  the  near  point  causes  at  first  no  in- 
convenience. According  to  Donders,  the  average  distance  of  the 
near  point  in  the  emmetropic  eye  at  20  years  of  age  is  3f  inches, 
at  35  years  about  6  inches :  and  it  is  very  seldom  that  there  is 
occasion  to  use  the  eyes  upon  objects  so  near.  When  the  near 
point  recedes  to  15  inches  or  more,  inconvenience  is  felt  in  all  oc- 
cupations which  require  distinct  vision  of  near  objects,  such  as 
reading,  sewing,  etc.  If  the  objects  are  placed  within  the  region 
of  distinct  vision, — that  is,  beyond  the  near  point, — the  retinal 
images  become  too  small  to  admit  of  continuous  vision ;  upon 
bringing  the  objects  within  the  near  point  the  retinal  images  be- 
come larger,  but  at  the  same  time  are  rendered  indistinct  by  cir- 
cles of  diffusion.  This  indistinctness  of  the  retinal  images  is  less 
than  it  otherwise  would  be  from  the  fact  that  simultaneously  with 
the  limitation  of  accommodation  the  pupil  becomes  smaller  and 
the  circles  of  diffusion  are  correspondingly  decreased.  PresbyojDes 
seek,  therefore,  in  every  occupation  the  greatest  possible  amount 
of  light;  in  the  evening,  for  instance,  when  reading,  they  will 
hold  the  light  between  the  book  and  their  eyes  in  order  by  strong 
illumination  to  reduce  as  much  as  possible  the  size  of  the  pupil. 

The  senile  changes  in  the  lens  cause  not  only  a  withdrawal  of 
the  near  point,  but  may  affect  the  far  point  in  the  same  way.  The 
lens  is  known  to  consist  of  a  great  number  of  layers,  whose  in- 
dices of  refraction  increase  from  the  periphery  toward  the  centre, 
and  it  has  been  proved  that  by  reason  of  this  arrangement  the 
resulting  focal  length  is  shorter  than  it  would  be  if  the  entire 
lens  possessed  the  refracting  power  of  the  nucleus.     Now,  we 

*  Arch.  f.  Ophth.,  Bd.  ix.  2,  pag.  19. 


PRESBYOPIA.  27 

have  ground  to  believe  that  from  the  senile  changes  of  the  lens 
its  cortical  part  becomes  harder,  so  that  its  refracting  power  more 
nearly  approaches  that  of  the  nucleus ;  an  increase  of  focal  dis- 
tance is  the  result.  Moreover,  in  extreme  old  age  the  lens  ap- 
pears to  become  actually  flatter,  a  further  cause  for  the  diminution 
of  refraction.  In  this  way  hypermetropia  may  develop  in  eyes 
originally  emmetropic. 

The  diminution  of  the  range  of  accommodation  by  a  with- 
drawal of  the  near  point  from  the  eye  is,  then,  to  be  called  pres- 
byopia only  when  it  is  a  co-symptora  of  senile  changes  in  the  eye. 
These  changes  are  numerous.  All  the  refracting  media  of  the  eye 
become  less  transparent;  this  is  noticeable  when  one  compares 
ophthalmoscopically  a  senile  eye  with  a  youthful  one ;  the  ante- 
rior chamber  becomes  shallower;  the  iris  loses  its  motility;  the 
pupil  becomes  smaller,  and  often  does  not  dilate  normally  upon 
the  use  of  atropine;  the  choroid  and  membrane  of  Descemet  (the 
last,  fortunately,  as  a  rule,  only  near  the  corneal  margin)  become 
thickened  and  uneven ;  phosphate  of  lime,  as  Donders  has  shown,* 
is  deposited  in  the  sclera;  the  muscle  of  accommodation  atrophies; 
the  retina  in  its  vessels  and  in  the  structure  of  its  peripheral  parts 
also  shows  changes  which  must  be  regarded  as  senile.  Dimin- 
ished clearness  of  vision  follows  all  these  phenomena.  We  thus 
find  presbyopia  to  be  a  co-symptom  of  a  considerable  series  of 
changes,  and  must,  therefore,  regard  the  withdraM'al  of  the  near 
point  as  a  normal  phenomenon  only  when  it  stands  in  due  pro- 
portion to  the  age.  Emmetropes,  on  an  average,  first  experience 
the  inconveniences  of  presbyo])ia  between  the  forty-fifth  and 
fiftieth  years  of  life.  Only  very  sharp-sighted  eyes  can,  at  a 
greater  age,  be  used  by  the  hour  in  reading  or  writing  without 
experiencing  fatigue. 

Premature  presbyopia  occurs  in  connection  with  premature 
marasmus,  after  prostrating  sicknesses,  with  incipient  cataract  and 
with  the  development  of  glaucoma. 

The  diagnosis  of  presbyopia  is  easy.  It  is  first  to  be  ascer- 
tained that  the  vision  for  distance  is  good,  then  that  the  indistinct- 
ness of  near  objects  is  corrected  immediately  by  weak  convex 
lenses,  and,  finally,  that  the  diminution  of  accommodation  stands 

*  Arch.  f.  Ophth.,  ix.  2,  pag.  217 


28  PRESBYOPIA. 

in  the  proper  relation  to  the  age  of  the  patient.  Paralysis  of 
accommodation  is  partly  thus  excluded,  partly,  also,  by  the  beha- 
vior of  the  pupil.  As  a  rule,  the  pupil  is  contracted  in  presbyopia 
and  dilated  in  paralysis  of  accommodation. 

The  treatment  consists  in  substituting  convex  lenses  for  the  lost 
power  of  accommodation.  So  soon  as  presbyopia  causes  incon- 
venience which  is  relieved  by  the  use  of  weak  convex  lenses  {-^ 
to  4^),  such  spectacles  should  always  be  used  for  work.  It  is 
useless,  by  straining  the  eyes,  to  attempt  to  postpone  the  use  of 
glasses,  and  it  is  equally  useless  to  a'dopt  them  so  long  as,  in  spite 
of  the  removal  of  the  far  point,  continuous  reading  or  writing 
causes  no  inconvenience. 

The  strength  of  the  glasses  to  be  prescribed  depends  upon  the 
nature  of  the  patient's  occupation.  The  farther  his  near  point 
has  receded  beyond  the  distance  of  the  objects  on  which  he  uses 
his  eyes,  the  stronger  the  glasses  which  he  requires.  For  reading 
and  writing  it  generally  suffices  to  bring  the  near  point  up  to 
a  distance  of  from  12  to  15  inches.  In  simple,  uncomplicated 
presbyopia,  with  fair  acuteness  of  vision,  the  choice  of  proper 
spectacles  may  usually  be  left  with  the  patient.  From  time  to 
time,  as  the  near  point  gradually  recedes  from  the  eye,  somewhat 
stronger  glasses  must  be  chosen.  For  healthy  eyes  it  is  better  to 
use  uncolored  glasses.  The  blue  ones,  which  have  become  per- 
haps too  fashionable,  are  at  first  very  agreeable,  but  since  they 
deprive  the  retina  of  the  normal  stimulus  of  white  light,  the  eye 
becomes  too  sensitive;  hence  having  once  begun,  it  is  necessary  to 
continue  wearing  them. 

DETERMINING   ACUTENESS   OF    VISION. 

We  have  said  that  in  making  the  diagnosis  of  presbyopia  it  is 
necessary  to  determine  the  acuteness  of  vision ;  we  must  now  con- 
sider the  method  of  doing  it.  A  sufficient  judgment  may  be 
formed  by  trying  the  acuteness  of  vision  by  test  type  of  varying 
sizes,  such  as  Jaeger's.  In  many  respects,  however,  Snellen's  test 
letters  are  better.  They  are  more  exact,  and  the  results  are  more 
easily  compared  with  each  other.  These  letters  increase  in  size 
according  to  a  definite  proportion. 

The  most  suitable  objects  appear  to  be  black  letters,  of  sizes 
so  arranged  that  they  are  seen  plainly  by  the  normal  eye  under 


DETERMINING    ACUTENESS   OF    VISION.  29 

an  ansrle  of  five  minutes.  The  thickness  of  the  lines  and  smaller 
parts  of  the  letters  is  exactly  one-fifth  their  height,  so  that  the  dif- 
ferent parts  of  the  letters  are  included  in  an  angle  of  one  minute, 
while  the  whole  letter  is  included  in  an  angle  of  five  minutes. 
The  letter  C,  for  example,  in  comparison  with  the  letter  O,  shows 
an  interruption  with  a  visual  angle  of  one  minute.  Accordingly 
this  series  of  letters  is  so  arranged  that  the  test  letters,  No.  I,  one 
foot  distant,  No.  II,  two  feet  distant,  No.  XX,  twenty  feet  distant, 
and  No.  C,  one  hundred  feet  distant,  are  all  included  in  the  same 
visual  angle  of  five  minutes.  If,  for  iustanee.  No.  XX  is  dis- 
tinctly seen  at  twenty  feet,  but  not  No.  I  at  one  foot,  it  shows 
normal  acuteness  of  vision,  but  that  probably  the  accommoda- 
tion is  insufficient  to  adjust  the  eye  for  a  distance  of  one  foot. 
This  probability  becomes  a  certainty  if  by  the  use  of  the  proper 
convex  lenses  No.  I  is  also  plainly  seen  at  a  distance  of  one 
foot. 

Again,  if  No,  I  is  seen  distinctly  at  a  distance  of  one  foot,  but 
not  No.  XX  at  twenty  feet,  there  is  normal  acuteness  of  vision,  but 
there  is  reason  to  suspect  the  existence  of  myopia.  This  suspicion 
is  confirmed  if  with  the  proper  concave  lenses  No.  XX  is  seen 
distinctly  at  twenty  feet. 

If  after  the  correction  of  any  existing  anomaly  of  refraction 
the  patient  cannot  see  No.  XX  at  a  distance  of  twenty  feet,  but 
only  at  a  distance  of  perhaps  ten  feet,  there  exists  a  deficiency  in 
the  acuteness  of  vision.  The  degree  of  this  deficiency  may  be 
expressed  by  a  fraction  whose  numerator  is  the  number  of  feet  at 
which  the  letters  are  seen,  and  whose  denominator  is  the  number 
of  feet  at  which  they  should  be  seen.  In  the  example  just  given 
there  is  an  acuteness  of  vision  of  1|-  =  i. 

The  examination  of  the  condition  of  vision  is  conducted  as 
follows.  The  test  letters  are  set  up  in  a  well-lighted  position  in 
a  room  twenty  feet  long  or  more.  If  now,  for  example,  No. 
XX  is  read  at  a  distance  of  twenty  feet,  the  acuteness  of  vision 
is  |-|,  that  is  =  1.  Persons  who  see  No.  XX  at  more  than  twenty, 
say  at  twenty-five  feet,  possess  an  acuteness  of  vision  of  ff ,  or 
one  exceeding  the  normal  average ;  such  cases  are  not  uncommon 
among  young  individuals.  If,  on  the  contrary,  No.  XX  is  not 
seen  at  a  distance  of  twenty  feet,  but  the  patient  must  ajiproach 
nearer  in  order  to  distinguish  the  different  letters,  there  is  a  dimi- 


30  DETEPwMINING    ACUTENESS    OF   VISION. 

nation  in  the  acuteness  of  vision,  and  it  is  to  be  expressed  in  the 
manner  above  described. 

It  is  in  many  respects  more  convenient  to  allow  the  distance 
between  the  test  letters  and  the  patient's  eye  to  remain  unchanged, 
and  to  write  as  numerator  of  the  fraction  the  number  which  is 
seen  with  normal  vision  at  that  distance,  and  as  denominator  the 
number  which  the  patient  actually  sees ;  for  instance,  if  not  No. 
XX  but  No.  LXX  are  the  smallest  letters  to  be  seen  at  a  distance 
of  twenty  feet,  the  acuteness  of  vision  is  j^. 

In  using  these  test  letters  it  should  be  remembered  that  it  is  by 
average  daylight  that  the  letters  are  recognized  at  the  given  dis- 
tances. AVith  intense  illumination  they  can  be  seen  at  even  a 
greater  distance.  The  changes  in  the  intensity  of  daylight,  which 
are  de])endent  upon  variations  in  the  weather,  are  a  source  of  error 
difficult  to  avoid. 

Tiic  proposition  to  abandon  daylight  and  conduct  this  examina- 
tion by  artificial  light  is  also  objectionable,  for  artificial  light  is 
likewise  subject  to  considerable  variations  of  intensity,  is  difficult 
to  control,  and  further,  when  we  conduct  a  patient  out  of  the 
daylight  into  a  room  artificially  lighted  in  order  there  to  try  his 
acuteness  of  vision,  an  adaptation  of  the  retina  to  the  changed 
illumination  must  first  take  place.  The  laws  according  to  which 
the  retina  adapts  itself,  especially  in  pathological  conditions,  to 
light  of  different  degrees  of  intensity,  are  as  yet  imperfectly 
understood. 

The  unavoidable  variations  in  the  intensity  of  daylight  seem 
the  simplest  to  deal  with.  In  my  own  private  practice  I  have 
found  it  convenient  to  use  a  modification  of  the  usual  expression 
for  the  acuteness  of  vision.  If,  according  to  Snellen's  plan,  the 
denominator  of  the  fraction  be  the  number  of  the  test  type  recog- 
nized by  the  patient,  and  the  numerator  the  number  of  feet  at 
which  he  sees  them,  then  it  is  only  the  denominator  which  is 
affected  by  changes  in  the  illumination ;  the  errors  from  this 
source  become  less  when  we  subject  the  numerator  also  to  the 
same  influences.  I  prefer,  therefore,  to  write  as  numerator  of  the 
fraction  that  number  of  the  test  type  which  I  can  recognize 
simultaneously  with  and  at  the  same  distance  as  the  patient;  as 
denominator,  I  write  the  number  of  the  type  which  the  patient 
reads.    In  this  way  some  but  not  all  sources  of  error  are  avoided. 


MYOPIA.  '31 


MYOPIA. 


Myopia  exists  when,  accommodation  being  relaxed,  parallel  rays 
falling  upon  the  cornea  are  not  united  to  an  image-point  upon  the 
retina,  but  intersect  each  other  in  front  of  it.  Of  course  under 
these  circumstances  every  distant  object  casts  upon  the  retina  a 
circle  of  diiFusion.  The  retinal  images  of  distant  objects  are  there- 
fore diifuse  and  indistinct.  In  order  to  cast  a  sharp  image  upon  the 
retina  the  luminous  point  or  object  fixed  must  approach  the  eye  to 
within  a  certain  distance.  The  far  point  of  distinct  vision  does  not 
lie  as  M'ith  the  emmetropic  eye  at  an  infinite  but  at  a  finite  distance. 

The  position  of  the  far  point  can  be  directly  determined  by 
ascertaining  the  greatest  distance  at  which  test  type  of  the  proper 
size  can  be  read.  If,  for  instance,  the  patient  read  No.  I  of 
Snellen's  test  type  at  12  inches,  but  cannot  read  No.  II  at  24 
inches,  it  may  be  assumed  with  certainty  that  his  far  point  lies 
between  12  and  24  inches,  and  it  remains,  by  further  experiments, 
to  determine  more  exactly  its  position. 

It  is  advisable  in  all  cases  to  begin  the  examination  in  this 
manner  and  then  to  verify  and  perfect  the  result  by  giving  to 
the  rays  from  a  distant  object,  by  the  help  of  a  concave  lens,  a 
divergence  such  as  if  they  had  proceeded  from  the  far  point.  If, 
for  instance,  the  far  point  lie  at  16  inches,  and  we  place  imme- 
diately in  front  of  the  patient's  eye  a  concave  lens  with  a  negative 
focal  length  of  16  inches,  then  will  the  parallel  rays  after  their 
refraction  in  the  concave  lens  so  diverge  as  if  they  had  proceeded 
from  the  negative  focal  point  of  the  lens ;  but  according  to  our 
supposition  this  negative  focal  point  coincides  with  the  for  point ; 
both  lie  16  inches  from  the  eye,  the  distance  between  the  concave 
lens  and  the  eye  not  being  considered.  Under  these  circumstances 
there  is  distinct  distant  vision,  and  upon  using  the  test  type  for  dis- 
tance, normal  acuteness  of  vision  is  found.  A  concave  lens  weaker 
than  — yig  would  not  produce  this  result,  for  its  negative  focal  ])oint 
would  lie  at  a  greater  distance  from  the  eye  than  the  far  point ; 
but  with  a  stronger  lens,  for  instance  with  —  -^^  or  —  ^^,  dis- 
tant vision  is  still  possible;  the  rays  falling  parallel  upon  the 
lens  diverge  after  their  refraction  in  it,  as  if  they  had  proceeded 
from  a  point  14  or  12  inches  distant,  and  a  myopic  eye  whose  far 
point  lies  16  inches  distant,  can  by  a  slight  effort  of  accommodation 


32  MYOPIA. 

adjust  itself  for  these  distances.  Since,  however,  we  wish  to  de- 
termine the  optical  adjustment  of  the  eye  when  its  accommodation 
is  fully  relaxed,  we  have  the  important  rule  that  only  the  weakest 
concave  lens  with  which  distant  vision  is  possible  gives  the  proper 
expression  for  the  position  of  the  far  point.  One  ought  not  to 
trust  the  subjective  impressions  of  the  patient ;  his  simple  state- 
ment that  he  sees  better,  is  not  sufficient  unless  in  connection 
with  it  the  reading  of  the  test  letters  shows  a  perceptible  im- 
provement in  vision.  Weaker  and  weaker  glasses  should  be  tried 
till  one  is  found  which  diminishes  the  sharpness  of  vision ;  the 
limit  is  then  passed. 

If  acuteness  of  vision  be  diminished,  as  is  usually  the  case  in 
the  high  grades  of  myopia,  then  the  weakest  concave  lens  which 
gives  the  best  attainable  vision  must  be  regarded  as  giving  ap- 
proximately the  correct  expression  for  the  degree  of  myopia. 

If  the  position  of  the  far  point  requires  the  employment  of  a 
moderately  strong  concave  lens,  say  — -^  or  more,  there  is  a  very 
simple  method  of  determining  whether  it  is  too  strong  or  not. 
Move  the  lens,  and  of  course  at  the  same  time  its  negative  focal 
point,  gradually  away  from  the  eye ;  if  with  the  lens  close  to  the 
eye  its  negative  focal  point  coincided  with  the  far  point,  then  upon 
withdrawing  the  lens  its  focal  point  will  be  removed  beyond  the 
far  point,  and  vision  loses  its  distinctness;  if  upon  Avithdrawing 
somewhat  the  lens  vision  is  as  distinct  or  even  more  distinct  than 
with  the  lens  held  close  to  the  eye,  it  shows  that  the  concave  lens 
is  too  strong.  In  the  case  of  strong  concave  lenses  the  distance 
between  the  eye  and  the  lens  should  not  be  neglected ;  if,  for 
instance,  it  be  ^  inch  and  the  far  point  lie  at  3  inches,  then  will 
the  negative  focal  point  of  a  lens  —  ^^  coincide  with  the  far  point. 

The  degree  of  myopia  is  determined  by  the  position  of  the  far 
point;  if  it  lie  at  16  inches  the  degree  of  myopia  is  expressed  by 
M^;  if  it  lie  at  3  inches,  by  M^.  That  concave  lens  whose 
negative  focal  point  corresponds  with  the  far  point  is  called  the 
neutralizing  lens.  The  far  point  of  an  eye  provided  with  a  neu- 
tralizing lens  lies,  as  it  does  in  the  emmetropic  eye,  at  an  infinite 
distance. 

ANATOMICAL    CHANGES    IN    MYOPIA. 

Formerly  the  optical  cause  of  myopia  was  thought  to  be  too 
great  a  curvature  of  the  cornea.     By  ophthalmometric  measure- 


MYOPIA,   ANATOMICAL  CHANGES.  33 

ments,  Donclers  attained  the  unexpected  result  that  the  radius  of 
curvature  of  the  cornea  is  generally  greater  in  the  case  of  myopes 
than  with  emraetropes.  Of  coarse  a  too  great  curvature  of  the 
cornea,  when  it  exists,  will  cause  myopia.  The  same  is  true  of 
the  lens.  Changes  in  it  may  cause  myopia,  but  such  cases  do 
not  often  occur.  A  forward  displacement  of  the  lens  must,  for 
optical  reasons,  increase  the  refractive  condition  ;  this  seems,  how- 
ever, to  be  an  infrequent  cause  of  myopia.  Shortsightedness 
seems  to  be  oftener  caused  by  an  increase  of  the  index  of  refrac- 
tion, particularly  in  the  nucleus  of  the  lens.  The  condition  may 
be  easily  recognized  ophthalmoscopically,  if  the  pupil  be  large 
enough,  or  has  been  dilated  by  mydriatica.  The  reflection  from 
the  nucleus  of  the  lens  is  generally  stronger  than  normal,  as  well 
upon  examination  by  daylight  with  the  naked  eye  as  by  focal 
illumination  ;  upon  ophthalmoscopic  illumination,  especially  with 
a  weak  mirror,  the  nucleus  appears  evidently  differentiated  from 
the  cortical  part  of  the  lens ;  this  can  be  best  seen  by  making 
slight  movements  of  the  mirror.  These  changes  occur  as  the 
prodroraa  of  nuclear  cataract,  both  in  eyes  previously  healthy 
and  in  those  recovered  from  glaucoma.  They  often  occur,  also, 
as  one  of  the  many  complications  of  myopia  depending  upon  an 
elongation  of  the  axis  of  the  eye.  Under  the  title  "  Diseases  of 
the  Accommodation"  it  will  be  shown  that  aj^parent  myopia  may 
be  caused  by  a  continuous  tension  of  the  accommodation. 

The  most  frequent  and  important  cause  of  myopia  is  the 
elongation  of  the  axis  of  the  eye.  The  other  diameters  are  not 
unfrequently  somewhat  increased.  As  a  rule,  however,  the  axis 
is  most  elongated,  and  the  eye  assumes  therefore  an  ellipsoid 
form.  The  distention  of  the  membranes  occurs  mostly  at  the 
posterior  part  of  the  eye,  involving  generally  the  region  of  the 
optic  nerve.  The  greatest  diameter  of  the  eye,  therefore,  very 
nearly  coincides  with  its  axis ;  it  may,  however,  deviate  laterally, 
generally  toward  the  median  side.  According  to  E.  v.  Jaeger,* 
the  greatest  expansion  may  occur  even  on  the  median  side  of  the 
optic  nerve. 

This  anomaly  of  form  was  first  described  by  Scarpa.  Its  desig- 
nation as  "  staphyloma  posticum"  is  not  exactly  appropriate,  inas- 

*  Einstellungen  des  dioptrischen  Apparates,  Wien,  1861,  pag.  54, 


34 


MYOPIA,    ANATOMICAL    CHANGES. 


After   Domlers,     Anomalieu 
der  Refraction,  etc,  Fig.  145. 


Fig.  9. 


much  as  in  uncomplicated  myopia  the  protrusion  is  by  no  means 
so  circumscribed  and  prominent  as  in  anterior  scleral  staphyloma. 
In  spite  of  the  elongation  of  the  axis,  the  eye  maintains,  as  shown 
in  Fig.  8,  a  regular  form.  The  sclera  is 
expanded  and  thinned  throughout  its  whole 
extent,  on  the  temporal  more  than  on  the 
median  side,  and  most  of  all  in  the  region 
of  the  posterior  pole.  So  thin  may  it  be- 
come that  this  part  upon  enucleated  eyes 
appears  blue,  like  an  anterior  staphyloma, 
and  if  the  cornea  be  turned  to  the  light, 
an  inverted  image  of  outer  objects  will  be 
plainly  seen  cast  upon  the  attenuated  portion.  Indeed,  even 
during  life  the  bluish  color  in  the  region  of  the  posterior  pole  can 

be  often  seen  by  causing 
the  patient  to  turn  his 
cornea  strongly  inward. 
These  changes  exert 
a  marked  influence  upon 
the  place  where  the  op- 
tic nerve  enters  the  eye. 
The  stretching  of  the 
membrane  in  the  region 
of  the  posterior  pole 
pushes  the  optic  nerve 
somewhat  aside  toward 
the  median  line. 

Moreover,  the  two 
nerve-sheaths  change  in 
their  relations  toward 
each  other.  Since  the 
inner  nerve-sheath  is 
adherent  to  the  nerve 
itself,  while  the  outer 
one  is  continuous  with 
the  sclera,  it  follows  that 
a  distention  of  the  latter 
causes  a  traction  upon  the  external  sheath,  drawing  it  from  the 
other  and  increasing  the  space  between  the  two.     (See  Fig.  9.) 


From  Bonders,  1.  c.  Fig.  147.  The  space  c  between  the 
Inner  and  outer  nerve-sheaths  widens  as  it  approaches  the 
sclera;  the  largest  part  of  the  outer  sheath  a"  blends  with 
the  sclera  ;  a  thinner  membrane,  a',  runs  toward  the  optic 
nerve,  and  is  continuous  with  the  inner  nerve-sheath  h'. 
At  this  place  the  sclera  consists  therefore  of  only  a  thin 
lamella,  a',  which  is  in  relation  posteriorly  with  the  loose 
areolar  tissue  c',  and  which  anteriorly  is  covered  by  the 
atrophied  and  depigmented  choroid  d' ;  f  is  the  lamina 
cribrosa,  and  the  tissue  n,  above  the  choroid,  is  the  retina. 


MYOPIA,  ANATOMICAL   CHANGES.  85 

According  to  Dondcrs,  the  place  of  entrance  of  tlie  optic  nerve 
on  the  outer  surface  of  the  sclera  may  attain  by  this  widening  a 
diameter  of  8  millimetres  or  more,  so  as  to  present  an  appearance 
as  if  the  optic  nerve  Avere  set  upon  a  second  terrace  of  the  staphy- 
loma. This  widening  of  the  space  between  the  outer  and  inner 
sheath  of  the  optic  nerve  is  mentioned  by  Von  Ammon.* 

The  investigations  of  E.  v.  Jaeger  f  show  that  the  same  thing 
occurs  in  myopia  of  a  low  grade. 

As  a  rule  the  choroid  remains  normal  in  its  anterior  part,  but 
the  more  it  approaches  the  expanded  part  the  thinner,  paler  and 
more  atrophied  does  it  become.  These  changes  are  greatest  close 
to  the  optic  disc,  so  that  here  nothing  remains  of  the  choroid  but 
a  thin,  structureless,  transparent  membrane,  containing  no  trace 
of  blood-vessels  or  even  capillaries.  Beyond  this  fully-atrophied 
part,  however,  the  anatomical  elements  of  the  choroid  are  but 
little  changed.  The  pigmented  epithelium  forms  a  uniform 
layer ;  the  individual  cells  lose  more  or  less  of  their  pigment 
molecules  in  the  greatly  distended  part,  and  may  even  become 
colorless ;  in  places  they  are  noticeably  enlarged  and  flattened. 
The  branching  pigmented  cells  of  the  choroidal  stroma  behave  in 
the  same  way ;  anteriorly,  where  the  choroid  retains  its  normal 
thickness,  they  remain  entirely  normal ;  further  back  they  con- 
tain less  pigment,  and  finally  none  at  all. 

A  further  consequence  of  the  distention  suffered  by  the  choroid 
is  that  its  anterior  portions,  the  ciliary  body,  the  iris  and  at  the 
same  time  the  lens,  move  backward  ;  this  accounts  for  the  very 
frequent  deepening  of  the  anterior  chamber  in  myopic  eyes.  The 
ciliary  muscle  having  a  tendinous  attachment  on  the  edge  of  the 
cornea,  experiences  from  this  process  a  traction  which  may  induce 
atrophy. 

In  uncomplicated  cases  of  myopia  the  retina  shows  no  recog- 
nizable changes. 

OPHTHALMOSCOPIC  APPEARANCE. 

In  myopia,  changes  are  almost  always  observable  about  the 
optic  disc;  as  a  rule  there  is  a  sharply-defined  sickle-shaped  or 
crescentic  spot  on  the  temporal  side  and  close  to  the  disc,  where 

*  Von  Ammon,  Zeitsclirift  fiir  die  Ophthalinologie,  Bd.  ii.  pag.  250. 
f  Einstellungen  des  dioptr.  Apparates,  Taf.  ii.  Fig.  18  bin  29. 


36  MYOPIA,  OPHTHALMOSCOPIC   APPEARANCE. 

more  or  less  atrophy  of  the  choroid  exists.  In  many  cases  it  is 
only  the  pigmented  epithelium,  which  is  faded  or  degenerated  so 
that  the  choroidal  stroma  can  be  distinctly  seen.  In  most  cases, 
however,  there  is  an  unmistakable  atrophy  of  the  stroma,  and  the 
entire  choroid  is  transformed  into  a  thin,  structureless,  transparent 
membrane,  which  does  not  weaken  in  any  degree  the  white  reflex 
from  the  sclera.  In  many  cases  one  still  sees  a  few  large  vessels 
remaining  in  the  region  of  the  choroidal  atrophy.  These  various 
appearances  are  observed  quite  constantly.  Often  with  a  high  de- 
gree of  myopia,  and  with  an  atrophied  part  equal  in  width  to  the 
diameter  of  the  disc,  only  the  pigment-epithelium  will  have  lost 
its  color,  while  in  other  cases  of  a  mild  form  of  myopia  there  will 
be  only  a  small  but  fully  atrophied  crescent  about  the  margin  of 
the  disc. 

The  atrophied  part  is  often  separated  from  tiie  adjoining  cho- 
roid by  a  rather  regular  dark  line.  Some  cases,- where  the  atrophy 
has  extended  farther  over  the  choroid,  show'  traces  of  several  such 
concentric  curved  lines.  In  other  cases  the  atrophied  part  has  a 
more  or  less  irregular  form. 

In  the  majority  of  cases  this  circumscribed  choroidal  atrophy 
occurs  on  the  temporal  side  of  the  optic  nerve,  and  s})reads  from 
it  toward  the  macula  lutea,  generally,  hoAvever,  Avithout  reaching 
it.  The  increase  of  the  atrophied  region  does  not  depend  alone 
upon  an  implication  of  the  adjoining  choroidal  tissue  in  the  degen- 
erative process,  but  at  the  same  time  upon  a  further  stretching  of 
the  already  thin  and  yielding  part;  in  this  way  the  distance  be- 
tween the  macula  lutea  and  the  optic  nerve  increases,  and  the 
latter  becomes  more  displaced  toward  the  median  line. 

In  high  degrees  of  myopia  the  choroidal  atrophy  often  extends 
around  the  entire  optic  nerve;  the  disc  appears  surrounded  by  a 
white  ring,  whose  breadth  is  generally  greater  on  the  temporal 
than  on  the  median  side. 

In  rare  cases  the  atrophied  spot  is  below  the  optic  nerve ; 
oftener  its  position  is  under  and  outward,  or  over  and  outward, 
from  the  optic  nerve.  Its  rarest  position  is  above  the  optic  nerve, 
and  such  cases  do  occur.*  A  beginning  of  the  choroidal  atrophy 
upon  the  median  side  of  the  optic  nerve  has  been  observed. 

*  Streatfeild,  Ophth.  Hosp.  Kep.,  v.  1,  pag.  80,  and  Mauthner,  Lehrbuch 
der  Oplithalmoscopie,  pag.  422. 


MYOPIA,   OPHTHALMOSCOPIC  APPEARANCE.  37 

These  small  atrophied  spots  often  seem  to  lie  at  a  different 
level  from  the  other  parts  of  the  fjindus, — at  least  it  is  often  no- 
ticed that  the  retinal  vessels  in  passing  from  the  periphery  upon 
the  atrophied  part  experience  a  change  of  direction,  whicli  is  to  be 
regarded  as  the  expression  of  a  transition  from  one  surface  to 
another  lying  deeper.  Donders*  and  Manthnerf  regard  these 
cases  as  exceptional,  and  I  have  also  formerly  expressed  my- 
self in  the  same  way,  since  in  cases  of  a  high  degree  of  myopia, 
with  wide-spread  choroidal  atrophy,  I  missed  the  oplithalmo- 
scopic  signs  of  the  difference  of  level.  The  case  is  somewhat  dif- 
ferent with  the  crescentic  spots  of  moderate  size  with  a  breadth 
less  than  that  of  the  disc.  Especially  when  they  are  sharply 
bounded  and  surrounded  by  the  dark  line  before  described,  do 
they  give  the  impression  of  a  slight  ectasia.  The  optic  disc  shows 
generally  in  these  cases  where  the  ectasia  affects  it  only  on  one 
side,  an  oblique  position,  the  side  corresponding  to  the  greatest 
diameter  of  the  ectasia  lying  deepest ;  and  besides  this,  we  have 
such  a  change  of  form  of  the  optic  nerve  that  its  transverse  sec- 
tion forms  an  oval,  whose  shortest  diameter  lies  in  the  same  direc- 
tion as  that  in  M'hich  the  ectasia  has  attained  its  greatest  extent. 
This  change  of  form  of  the  optic  nerve  is,  in  part  certainly,  only 
an  apparent  one;  its  dislocation  toward  the  median  wall  of  the 
eyeball  causes  us  to  see  it  in  a  more  oblique  position  than  normal, 
and  therefore  foreshortened ;  still  more  must  this  be  the  case 
where  the  disc  has  suffered  the  oblique  excavation  above  described. 
Where  the  choroidal  atrophy  is  of  slight  extent,  the  contour  of 
the  optic  nerve  is  generally  sharply  distinguishable  from  the  ad- 
joining white  scleral  region.  If  the  atrophy  involves  a  large  j^art 
of  the  fundus,  the  demarcation  of  the  optic  disc  generally  becomes 
very  indistinct. 

The  retinal  vessels  show  with  unusual  distinctness  upon  the 
white  background  of  the  sclera ;  for  this  reason  they  are  often 
visible  in  greater  numbers ;  they  are,  moreover,  less  sinuous  than 
normal. 

The  choroid  bordering  upon  the  atrophied  spot  may  appear 
wholly  unchanged,  but  sometimes  shoM'S  traces  of  a  slight  degree 
of  atrophy ;   it  appears  somewhat  lighter  and  more  transparent, 

*  L.  c,  pag.  300.  t  L.  c,  pag.  421. 


38  MYOPIA,    OPHTHALMOSCOPIC   APPEARANCE. 

and  its  intervascular  spaces  in  consequence  of  its  stretching  are 
somewhat  widened. 

This  circumscribed  choroidal  atrophy  is  almost  always  present 
in  myopia,  and  according  to  Donders  there  is  a  quite  uniform 
average  relation  between  the  extent  of  the  atrophy  on  the  one 
hand  and  the  degree  of  myopia  and  time  of  life  on  the  other. 
It  must  be  mentioned,  however,  that  in  this  respect  there  are  very 
considerable  individual  variations.  The  consecutive  atrophy  may 
be  very  slight,  with  a  quite  high  degree  of  myopia ;  and,  on  the 
other  hand,  in  emmetropes,  and  even  in  hypermetropes,  these 
white,  crescentic,  slight  ectasias  are  sometimes  seen  upon  the 
temporal  side  of  the  disc ;  they  are  observed  oftener  in  old  than 
in  young  persons.  The  condition  of  refraction  not  considered, 
the  o})hthalmoscopic  appearances  in  many  of  these  cases  are  ex- 
actly the  same  as  in  myopia.  On  the  other  hand,  however,  it  is 
unmistakable  that  in  this  matter  there  are  very  gradual  transitions, 
so  that  in  any  given  case  one  cannot  be  certain  whether  he  has 
before  him  an  atrophied  crescent  or  a  rather  broad  "scleral  stripe." 

At  all  events,  the  connection  between  myopia  and  atrophy  of 
the  choroid  is  undoubted.  It  only  remains  to  be  explained  why 
it  develops  so  constantly  on  the  temporal  border  of  the  optic 
nerve,  and  not  on  that  part  of  the  choroid  lying  near  the  visual 
axis.  It  is  to  be  remembered  that  around  the  optic  nerve  the 
choroid  is  closely  attached  to  the  sclera,  that  often  too  it  sends 
fibrous  processes  into  the  nerve  itself.  At  this  place,  therefore, 
the  choroid  cannot  so  easily  escape  the  strain  as  it  can  in  other 
localities  where  it  is  more  loosely  connected  with  the  sclera.  Now, 
since  the  eye  is  most  distended  in  its  antero-posterior  diameter,  it 
is  easy  to  see  why  the  choroidal  atrophy  should  begin  just  upon 
the  temporal  side  of  the  optic  nerve.* 

Nevertheless,  the  sharp  demarcation  which  many  of  these  cases 
show,  proves  that  certain  local  causes  limit  the  effect  of  the  disten- 
tion of  the  entire  choroid  to  a  sharply  circumscribed  region.  So, 
too,  the  fact  that  the  atrophy  often  extends  entirely  around  the 
optic  nerve  shows  that  the  nerve  itself  participates  in  the  process. 
In  this  connection  the  widening  of  the  space  between  the  two 


*  Comp.  Schweiggor,  Zur  path.  Anat.  der  Choroidea,  Arch.  f.  Opl.th.,  Bd, 
ix.  1,  pag.  195,  and  Donders,  Anomalien  der  Refraction,  pag.  820. 


MYOPIA,  OPHTHALMOSCOPIC   APPEARANCE.  39 

nerve-sheaths  recurs  at  once  to  the  mind.  The  elongation  of  the 
sagittal  diameter  stretches  the  sclera  equally  with  the  choroid,  and  a 
traction  must  necessarily  be  brought  to  bear  upon  the  outer  nerve- 
sheath,  which  is  continuous  with  the  sclera.  The  outer  nerve- 
sheath  yields  to  this  traction,  separates  from  the  inner  sheath,  the 
lamellas  of  the  sclera  nearest  the  disc  (Fig.  9,  a'h')  lose  their  sup- 
port and  become  stretched  and  thinned  in  proportion  as  the  space 
between  the  sheaths  becomes  greater.  The  same  happens  with 
the  choroid,  which  maintains  its  normal  attachments  to  the  inner 
surface  of  the  sclera,  the  border  of  the  optic  nerve  and  the  lamina 
cribrosa.  It  is  easy  to  understand  why  this  exceedingly  thin 
place  should  yield  to  the  normal  intraocular  pressure,  and  thus 
form  an  ectasia,  which,  to  be  sure,  is  generally  slight.  Exter- 
nally this  is  not  perceptible,  since  it  is  too  small  and  is  covered 
by  the  external  nerve-sheath.  These  conditions,  however,  are  no 
obstacle  to  the  ophthalmoscopic  examination.  For  the  recognition 
of  this  condition  the  choroid  need  not  be  fully  atrophied;  with  a 
very  slight  atrophy  of  the  choroid  about  the  optic  nerve  the  course 
of  the  retinal  vessels  is  often  sufficient  to  determine  the  existence 
of  a  slight  ectasia. 

If  in  a  high  degree  of  myopia  the  greatest  diameter  of  the  eye 
coincide  nearly  with  the  visual  axis,  the  outer  optic  nerve-sheath 
appears  to  separate  on  all  sides  from  the  inner  one,  and  the  cho- 
roidal atrophy  assumes  the  annular  form.  Donders  states  that 
such  was  the  case  in  the  eye  whose  optic  nerve  is  represented  in 
Fig.  9. 

Of  course  in  high  degrees  of  myopia  the  diffuse  atrophy  of  the 
choroid  caused  by  the  stretching  of  the  ocular  membranes  may 
easily  overstep  the  limits  bounded  by  tlie  outer  nerve-sheath. 
Nevertheless,  one  often  sees  in  these  cases  upon  the  white  scleral 
background  which  has  been  laid  bare  by  the  choroidal  atrophy,  a 
distinct  curved  line,  which  may  be  regarded  as  probably  the  line 
of  junction  of  the  external  nerve-sheath  with  the  outer  surface  of 
the  sclera, 

CAUSES    AND   COURSE. 

In  the  majority  of  cases  myopia,  or  at  least  a  predisposition 
to  it,  is  to  be  regarded  as  congenital  or  inherited.  On  the  other 
hand  it  is  certain,  and  one  hears  it  often  enough  confirmed  by  the 


40  MYOPIA,  CAUSES   AND   COURSE. 

myopes  themselves,  that  straining  the  eyes  favors  the  develop- 
ment of  myopia. 

The  clinical  history  of  hypermetropia  shows  that  a  long-con- 
tinued tension  of  accommodation  is  of  itself  not  enough  to  induce 
an  elongation  of  the  eye.  Nevertheless  it  might  be  otherwise  if 
the  sclera  possessed  diminished  power  of  resistance,  and  if  other 
conditions  were  present,  particularly  strong  convergence  of  the 
visual  axes  and  a  bowed  position  of  the  head.  The  first  is  asso- 
ciated with  an  increased  intraocular  })ressure,  which  favors  a  dis- 
tention of  the  sclera;  the  last  causes  a  passive  hypersemia,  which 
tends  in  the  same  direction.  All  these  conditions  almost  of  neces- 
sity exist  when  work  is  undertaken  in  an  insufficient  light.  The 
habit  which  children  early  acquire  of  reading  long  into  the  twi- 
light, and  the  use  of  ill-contrived  school-furniture,  are  both  fre- 
quent causes  of  myopia. 

Accordingly,  it  is  no  wonder  that  myopia  is  such  a  wide-spread 
abnormity.  It  occurs  in  early  childhood,  and  shows  with  the  in- 
crease of  years  a  progression  both  in  frequency  and  degree  of 
development. 

Although  for  the  majority  of  cases  Ave  must  regard  a  congenital 
weakness  of  the  posterior  part  of  the  sclera  as  the  primary  cause 
of  myopia,  it  is  certain  that  the  same  condition  maybe  an  acquired 
one.  The  circumstance  that  myopia  often  develops  in  children 
shortly  after  measles  or  scarlet  fever  goes  to  prove  this.  Myopia 
often  occurs  also  in  connection  with  cloudiness  of  the  cornea ;  this 
is  not  because  the  cornea  becomes  more  convex,  for  in  most  cases 
there  are  simultaneously  present  the  ophthalmoscopic  indications  of 
elongation  of  the  axis ;  it  is  more  probably  due  to  the  indistinct- 
ness of  the  retinal  images,  the  patient  seeking  to  compensate  by 
increase  in  size  for  what  he  loses  in  distinctness.  In  order  to 
obtain  larger  retinal  images,  the  patient  brings  his  eye  as  near  as 
possible  to  his  work;  a  bowing  of  the  head,  strong  tension  of  ac- 
commodation and  a  corresponding  convergence  of  the  visual  axes 
are  the  consequences. 

If  the  distention  of  the  sclera  be  once  established,  it  can  be 
easily  understood  how  intraocular  hypersemia  and  conditions  of 
slight  irritation  may  still  further  lessen  its  capacity  for  resistance 
and  render  the  distention  progressive.  On  the  other  hand,  one 
often  sees,  in  cases  with  great  distention  of  the  sclera  and  high 


MYOPIA,  CAUSES    AND    COURSE.  41 

degree  of  myopia,  choroidal  changes  which  must  be  regarded  as 
inflammatory.  This,  however,  does  not  justify  us  in  regarding 
the  process  as  an  inflammatory  one  from  the  beginning,  and  tlie 
atrophied  crescent  as  tlie  result  of  a  sclerotico-choroiditis  poste- 
rior. 

Myopia  may  remain  stationary  through  life,  or  at  an  advanced 
age  it  may  show  an  apparent  or  actual  decrease.  The  apparent 
decrease  is  due  to  the  contraction  of  the  pupil,  by  which  the  circles 
of  diffusion  are  made  smaller  and  the  images  of  distant  objects 
more  distinct.  An  actual  decrease  of  myopia  may  be  caused  by 
the  senile  changes  in  the  lens  before  referred  to. 

In  other  cases  myopia  is  rapidly  progressive  during  a  certain 
period  of  life,  generally  up  to  about  the  twenty-fifth  year,  and 
after  that  remains  stationary.  Finally,  it  may  happen  that  myopia 
remains  progressive  through  life, 

COMPLICATIONS   IN   MYOPIA. 

The  myope  receives  with  the  naked  eye  only  indistinct,  diffuse 
retinal  images  of  all  objects  lying  beyond  his  far  point.  In  low 
degrees  of  myopia  the  indistinctness  of  distant  vision  is  often  not 
so  great  as  to  cause  marked  inconvenience,  but  the  opposite  is 
true  in  high  degrees  of  myopia,  where  the  retinal  images  of  ob- 
jects only  a  few  feet  distant  are  very  confused.  If,  moreover,  the 
objects  are  insufficiently  illuminated,  as  in  the  twilight,  vision  will 
be  very  imperfect. 

The  size  of  the  circles  of  diffusion  increases  with  the  distance 
of  the  object  and  the  size  of  the  pupil. 

Myopes  are  often  better  able  than  emmetropes  to  recognize  very 
small  objects,  even  in  a  poor  light,  since  the  jx)sition  of  the  near 
point  allows  a  closer  approach  of  the  object. 

As  the  far  point  approaches  the  eye,  the  whole  range  of  accom- 
modation approaches  with  it,  so  that  without  any  lessening  of  the 
angle  included  by  the  accommodation  the  space  covered  by  accom- 
modation is  greatly  diminished.  If,  for  instance,  with  MyL  the 
action  of  accommodation  is  as  great  as  we  have  above  assumed  it 
to  be  in  the  emmetropic  eye,  that  is  ^=1,  the  position  of  the  near 
point  may  be  calculated  from  the  formula  -f  -j-  i:=^,  which 
becomes  ^2  +  4  =  3^-  The  whole  region  of  distinct  vision  lies 
between  the  points   3   inches   and  4   inches  distant,  while   the 

4 


42  COMPLICATIONS  IN   MYOPIA. 

einmetrope,  with  exactly  the  same  amount  of  accommodative 
power,  receives  distinct  retinal  images  from  4  inches  up  to  an 
infinite  distance. 

The  range  of  accommodation  of  myopic  eyes  may  be  determined 
by  finding  the  positions  of  the  far  and  near  points,  and  reckoning 
from  them  the  accommodation  ;  or  the  examination  may  be  made 
to  resemble  that  of  the  emmetropic  eye  by  removing  the  far  point 
to  an  infinite  distance,  by  the  use  of  a  neutralizing  lens^  and  then 
finding  the  near  point. 

The  behavior  of  the  relative  range  of  accommodation  is  of 
special  interest.  The  myope  learns  unconsciously  to  converge 
nearly  to  his  near  point  without  accommodating.  If,  for  instance, 
the  far  point  lie  at  8  or  10  inches,  the  eyes  (of  course  without 
glasses)  converge  to  nearly  this  distance  without  there  being  any 
simultaneous  tension  of  accommodation. 

Now,  since  myopes  are  much  seldomer  than  emmetropes  in  a 
position  to  use  their  near  points,  it  follows,  by  reason  of  the  change 
in  the  relative  range  of  accommodation,  that  less  demand  is  made 
upon  the  accommodative  power  of  the  myopic  than  of  the 
emmetropic  eye. 

In  other  respects,  however,  greater  demands  are  often  made  on 
the  myopic  thaii  on  the  emmetropic  eye;  particularly  is  this  the 
case  in  reference  to  the  convergence  of  the  visual  axes.  If,  with 
the  naked  eyes,  the  myope  wishes  to  see  distinctly  and  binocularly 
an  object  within  his  range  of  accommodation,  his  visual  axes  must 
converge  to  at  least  the  distance  of  his  far  [xyint.  In  only  mod- 
erate degrees  of  myopia  a  stronger  convergence  is  required  than  in 
emmetropic  eyes.  Moreover,  the  convergence  is  made  difficult  by 
two  circumstances. 

In  emmetropic  eyes  the  line  of  vision  does  not  intersect  the 
cornea  at  its  centre,  but  somewhat  toward  the  median  side,  A 
perpendicular  let  fall  upon  the  centre  of  the  cornea  will  form  with 
the  line  of  vision  and  on  the  external  side  of  it  an  angle  which 
we  designate  as  the  angle  oc'.  If  the  lines  of  vision  are  parallel, 
then  the  perpendiculars  let  fall  upon  the  centre  of  the  cornea  must 
be  divergent,  and  if  the  lines  of  vision  intersect  at  any  given  point, 
the  point  of  intersection  of  the  perpendiculars  must  be  at  a  greater 
distance.  In  myopia  the  deviation  of  the  line  of  vision  from  the 
centre  of  the  cornea  is  less  than  in  emmetropia,  and  consequently 


COMPLICATIONS   IX   MYOPIA.  43 

to  direct  the  eyes  upon  a  point  at  any  given  distance  there  must  be 
a  stronger  convergence  of  the  eyes,  and  a  greater  demand  upon, 
the  action  of  the  internal  recti  muscles,,  than  in  emmetropia. 

In  addition  to  this,  the  abnormal  shape  of  the  myopic  eye  im- 
pedes its  movements.  While  the  nearly  spherical  emmetropic  eye 
plays  like  a  ball-and-socket  joint  in  the  capsule  of  Tenon,  the 
myopic  eye,  on  account  of  its  elliptical  shape,  meets  with  consider- 
able resistance  to  all  lateral  rotation,  restricting  the  movement 
both  outward  and  inward.  But  while  a  slight  turning  of  the 
head  may  take  the  place  of  a  rotation  of  the  eye  outward,  no  such 
compensation  is  possible  when  it  is  desired  to  turn  both  eyes  simul- 
taneously toward  the  median  line.  This  difficulty  of  convergence 
Ls  the  reason  that  in  high  degrees  of  myopia  binocular  vision  for 
near  objects  is  relinquished,  especially  when  the  myopia  or  the 
acuity  of  vision  of  the  two  eyes  does  not  correspond.  For  reading, 
etc.,  the  best  eye  only  is  then  used,  while  the  axis  of  vision  of  the 
other  eye  is  not  directed  upon  the  point  fixed,  but  has  a  direction 
relatively  or  absolutely  divergent.  The  inconveniences  of  diplopia, 
which  one  would  expect  under  these  circumstances,  do  not  gener- 
ally occur,  becaase  the  attention  is  directed  only  upon  the  distinct 
retinal  images  in  the  one  eye,  while  the  retinal  images  of  distant 
objects  in  the  other  eye  being  diffuse  and  indistinct,  are  readily 
neglected. 

The  relinquishment  of  binocular  vision  under  these  circum- 
stances is  to  be  regarded  as  an  advantage.  These  myopes  do 
exactly  what  we  would  advise  them  to ;  they  avoid  all  straining 
of  accommodation  and  .strong  convergence  of  the  visual  axes,  and 
for  the  most  part,  too,  the  bent-over  position  of  the  head,  since  they, 
at  least  when  reading,  are  accustomed  to  hold  the  book  vertically 
and  the  head  erect.  This  insufficient  movement  of  the  eyes  is  to 
be  distinguished  from  an  insufficiency  of  the  muscles,  of  which 
we  have  yet  to  speak. 

Other  and  very  important  functional  disturbances  are  caused 
by  the  distention  of  the  membranes  in  high  degrees  of  myopia. 
In  the  first  place,  the  distention  of  the  retina  causes  a  separation 
of  the  perceptive  retinal  elements;  this,  in  high  degrees  of  myopia, 
causes  a  diminution  in  the  acuteness  of  vision.  Nevertheless, 
myopes  do  not  generally  complain  of  this.  Since  they  can  hold 
objects  nearer  the  eye,  they  use  a  larger  visual  angle,  and  can 


44  COMPLICATIONS   IN   MYOPIA. 

therefore  often  read  fine  print  easily,  although  for  distance  and 
with  concave  glasses  a  diminution  of  normal  vision  to  one-half 
or  one-third  is  already  evident. 

This  form  of  amblyopia  is  to  be  distinguished  from  a  diminu- 
tion of  vision  which,  in  high  degrees  of  myopia,  often  occurs  as 
one  of  the  symptoms  of  a  retinal  irritation.  The  stretching  which 
the  retina  and  other  membranes  suifer  in  the  myopic  eye  is  prob- 
ably the  cause  of  this  irritation.  Aside  from  the  diminution  of 
vision  in  such  cases,  there  are  speedy  fatigue  in  Avorking  and  a  feel- 
ing of  fulness  and  tension  in  the  eye;  often  too  the  eye  is  sensitive 
upon  light  pressure ;  besides  this  there  is  dazzling,  subjective  per- 
ception of  light  and  troublesome  myodesopia.  The  latter  is  often 
the  principal  inconvenience  which  myopes  complain  of;  the  mate- 
rial cause  of  this  is  always  small  elements  in  the  vitreous,  which 
are  also  present  and  visible  in  perfectly  normal  eyes.  In  eyes  not 
myopic  these  "mouches  volantes"  are  principally  noticed  when 
there  are  upon  the  retina  no  distinct  images  other  than  those  cast 
by  these  elements  of  the  vitreous, — that  is,  when  the  gaze  is  directed 
upon  a  uniform  surface.  Hence  myopes  not  unfrequently  find 
relief  from  this  inconvenience  in  the  use  of  concave  glasses,  which 
do  away  with  the  uniform  indistinctness  of  their  retinal  images. 

On  the  other  hand,  it  is  probable  that  in  many  cases  of  myopia 
the  myodesopia  is  actually  caused  by  microscopic  opacities  in  the 
vitreous,  since  a  cloudiness  often  develops  there  which  is  ophthal- 
moscopically  visible.  The  presence  of  such  opacities  is  the  rule 
with  those  wide-spread  choroidal  changes  which  accompany  high 
degrees  of  myopia  in  the  latter  half  of  life.,  The  vitreous  appears 
fluid  and  presents  under  the  microscope  small  opacities,  which, 
without  possessing  any  determinate  structure,  present  a  fibrous, 
granular  appearance.  These  are  either  fixed  by  threads  which  run 
off  and  end  in  the  sound  vitreous  tissue,  and  in  this  case  are  sit- 
uated generally  not  far  from  the  disc,  or  they  are  freely  movable 
in  the  fluid  substance,  and  swim  about  here  and  there  with  every 
movement  of  the  head.  Under  these  circumstances  there  is  often 
also  a  circumscribed  cloudiness  at  the  posterior  pole  of  the  lens 
(cataracta  polaris  posterior). 

In  high  degrees  of  myopia,  especially  in  advanced  age,  other 
changes  of  undoubted  inflammatory  nature  are  added  to  the  consec- 
utive choroidal  atrophy ;  they  are  principally  in  the  region  of  the 


COMPLICATIONS    IX    MYOPIA.  45 

equator  and  about  the  posterior  jwle.  In  the  former  position  tliey 
.appear  oftenest  in  the  under  part  of  the  choroid,  in  the  form  of 
round  spots  which  sometimes,  through  loss  of  color  and  atrophv, 
are  bright  red  or  white,  sometimes  are  noticeable  from  the  dark 
coloring  of  the  choroidal  epithelium ;  both  appearances  may  be 
combined,  presenting  bright  spots  with  black  edges.  On  account 
of  their  peripheral  position  they  do  not  cause  much  disturbance  of 
vision ;  they  are,  however,  symptomatic  of  a  predisposition  to  serious 
disease. 

The  changes  about  the  posterior  pole  of  the  eye  are  more  fre- 
quent. The  originally  crescentic  or  annular  choroidal  atrophy 
surrounding  the  disc  loses  its  regular  boundaries  and  spreads  ir- 
regularly, mostly  in  the  temporal  direction. 

Insular  atrophied  spots  appear  in  the  neighborhood,  and  finally 
coalesce  with  the  principal  one.  Black,  irregular  spots,  formed 
evidently  of  groups  of  changed  choroidal  epithelium,  often  appear 
upon  the  Mdiite  background. 

The  increase  in  size  of  Mariotte's  blind  spot,  under  these  cir- 
cumstances, ought  scarcely  ever  to  cause  disturbances  of  vision, 
since  the  inner  layer  of  the  retina  remains  intact,  and  therefore 
the  conducting  power  of  the  nerves  from  the  periphery  is  not 
diminished. 

On  the  contrary,  aflFections  of  the  macula  lutea,  occurring  simul- 
taneously with  the  above-mentioned  changes,  or  even  independent 
of  them,  give  rise  to  very  serious  disturbances  of  vision.  At  first, 
even  in  eyes  whose  vision  has  not  yet  suffered,  there  appear  a  num- 
ber of  irregular  bright  lines  of  perhaps  the  breadth  of  the  prin- 
cipal retinal  vessel,  or  somewhat  broader,  and  of  various  lengths. 
These  are,  perhaps,  consequences  of  the  stretching  which  in  places 
separates  the  pigment-cells  one  from  another,  or  flattens,  stretches, 
and  depigments  them.  If  central  vision  is  already  essentially 
affected,  we  generally  find  changes  of  an  inflammatory  nature  in 
the  macula  lutea,  irregularly  diffused  pigment  changes,  collections 
of  black  pigment  interspersed  with  bright-red  or  white  spots ;  or 
exactly  in  the  centre  of  the  macula  lutea  there  may  be  a  black 
spot,  of  about  the  size  of  the  optic  disc;  or  there  may  be  a  larger, 
bluish,  elevated  spot,  perhaps  surrounded  by  a  black  ring  of  pig- 
ment and  often  accompanied  by  hemorrhages  in  the  neighboring 
retina. 


46  COMPLICATIONS   IN   MYOPIA. 

In  rare  cases  it  happens  tliat  a  sharply  defined,  small  staphyloma 
develops,  independent  of  the  crescentic  atrophy  surrounding  the 
nerve,  and  separated  from  it  by  healthy  choroidal  tissue.  In 
one  case  which  I  observed  there  was  in  the  neighborhood  of  the 
macula  lutea  a  bright  spot  with  a  diameter  once-and-a-half  or 
twice  that  of  the  disc,  with  pigment-spots  sprinkled  over  it  and 
surrounded  by  a  black  ring;  it  was  evidently  excavated  and  there 
was  a  corresponding  defect  in  the  field  of  vision.  Streatfeild*  has 
described  a  similar  case. 

The  disturbances  of  vision  which  accompany  the  above-described 
changes  in  the  region  of  the  macula  lutea  are  dependent  partly 
upon  the  stretching  of  the  retina  in  this  region,  partly  upon  the 
mechanical  insulation  which  the  layer  of  rods  and  cones  suffers  by 
reason  of  changes  upon  the  surface  of  the  choroid,  and  partly  from 
disease  of  the  retina  itself.  The  patients  complain  of  a  trembling 
of  the  letters  when  reading,  of  irregular  curves  in  the  lines,  of  an 
oblique  position  and  irregular  form  of  the  individual  letters,  of 
clouds  or  dark  spots  in  the  centre  of  the  field,  or  finally  of  abso- 
lute inability  to  see  the  point  fixed  (scotoma  centrale). 

Donders  explains  the  trembling  of  the  lettei's,  by  the  presence 
in  the  macula  lutea  of  a  number  of  very  small  defects  (scotomata). 
Now,  with  the  movements  of  the  eye,  the  image  of  each  individual 
letter  falls  first  upon  some  spot  in  the  retina  which  is  sensitive, 
then  upon  one  insensitive  to  light,  so  that  it  alternately  appears 
and  disappears ;  at  the  same  time,  in  consequence  of  the  irregular 
displacement  of  the  layer  of  rods  and  cones,  the  shape  of  the  let- 
ters appears  changed. 

Forsterf  has  carefully  analyzed  the  phenomena  of  metamor- 
phopsia  (seeing  objects  distorted  and  inclined  from  their  true  po- 
sition), and  by  the  use  of  a  system  of  parallel  lines  has  shown 
that  in  a  limited  central  part  of  the  field  of  vision  the  curvatures 
of  the  lines  are  concentric.  The  metamorphopsia  also  occurs  in 
distant  vision  with  concave  glasses,  so  that,  for  instance,  the  bars 
in  the  window-sash  appear  crooked.  The  sensibility  of  the  mac- 
ula lutea  appears  reduced,  so  that  distinct  vision  is  only  possible 
by  intense  illumination.     At  the  same  time  the  bright  light  causes 

*  Ophthalmic  Hosp.  Eep.,  v.  1,  p.  84. 
f  Ophthalmologische  Beitnige,  1802. 


COMrLICATIONS   IN   MYOPIA.  47 

an  unpleasant  dazzling.  The  retina  is  quickly  fatigued  in  read- 
ing, etc. 

Upon  ophthalmoscopic  examination,  a  black  spot  appears  near 
the  macula  lutea,  often  surrounded  by  a  reddened  area  (hy}>ersemia 
or  extravasation).  Still,  F5rster  was  satisfied  that  the  portion  of 
the  retina  affected  by  metamorphopsia  was  much  larger  than 
that  in  which  changes  were  ophthalmoscopically  visible.  From 
the  concentric  curvature  of  the  lines  Forster  supposed  that  the 
sensitive  elements  of  the  retina  were  crowded  by  the  pathological 
process  toward  the  centre  of  the  diseased  jmrt.* 

While  the  above-mentioned  diseases  of  the  macula  lutea  at  least 
spare  the  periphery  of  the  field  of  vision,  it  happens  much  oftener 
in  myopic  than  in  previously  healthy  eyes,  that  sight  is  absolutely 
destroyed  by  detachment  of  the  retina. 

The  complication  of  myopia  with  glaucoma  will  be  considered 
under  the  head  of  the  last-named  disease. 

TREATMENT. 

A  cure  for  myopia  cannot  be  expected.  In  the  cases  of  ray- 
opes  who  have  strained  their  eyes  for  weeks  or  months,  one  often 
sees  that  rest  or  the  use  of  atropine  causes  some  withdrawal  of 
the  far  point ;  in  such  cases  there  has  been  no  change  in  the  con- 
dition of  refraction,  but  there  has  been  relief  to  a  sjjasm  of  ac- 
commodation, which,  when  discussing  hypermetropia,  we  shall 
describe  as  latent  accommodation.  There  is  more  to  be  done  in 
avoiding  the  development  of  myopia.  With  this  in  view,  it  is 
all-important  to  regulate  the  use  of  the  eyes.  Reading,  etc.,  at 
twilight  is  to  be  strictly  forbidden;  and  even  with  sufficient 
light,  work  ujx)n  very  near  objects  should  not  be  too  steadily 
pursued.  Above  all,  a  strong  bending  forward  of  the  head  is  to 
be  avoided.  Children  with  very  slight  myopia  often,  in  spite  of 
that  fact,  use  persistently  an  object  distance  from  4  to  6  inches ; 
this,  of  course,  involves  a  strong  tension  of  accommodation,  a  high 
degree  of  convergence  and  a  bowed  position  of  the  head.  It  is 
the  duty  of  parents  and  teachers  to  correct  this.     If  the  case  is 

*  An  affection  which  might  well  cause  this  is  the  retinitis  of  the  external 
layer,  described  by  H.  Muller.  Saemisch  (Beitrage  zur  Anatomic  des  Auges, 
1862)  has  shown  that  it  also  occurs  as  a  circumscribed  affection  of  the  macula 
!utea. 


48  MYOPIA,  TREATMENT. 

not  one  of  simple  bad  habit,  but  if  in  connection  with  distinct 
vision  there  exist  a  high  degree  of  myopia,  for  instance,  M^,  it 
is  at  all  events  advisable  to  remove  the  far  point  by  concave  glasses 
to  about  16  or  18  inches,  and  then  to  enforce  an  object  distance  of 
at  least  12  or  14  inches. 

To  insure  an  erect  position  of  the  head,  it  is  advisable  in  read- 
ing to  hold  the  book  in  the  hand,  and  in  writing  to  use  a  desk 
with  a  steeply-inclined  and  sufficiently  high  surface.  In  furnish- 
ing school-rooms  these  points  deserve  careful  attention.  It  is  for 
the  interest  of  society  to  combat  the  development  of  myopia  by  a 
proper  system  of  lighting  and  furnishing  school-rooms.* 

If  a  high  degree  of  myopia  appear  in  early  youth,  it  should 
influence  the  choice  of  an  occu])ation.  It  is  difficult,  however,  to 
lay  down  positive  rules  in  this  matter. 

In  most  cases  it  is  necessary  to  render  distant  vision  distinct  by 
the  use  of  proper  concave  lenses.  We  have  already  seen  that  the 
concave  lens  whose  focal  point  corresponds  with  the  far  point 
fulfils  this  condition,  and  we  shall  here  only  repeat  that  always 
only  the  weakest  lenses  with  which  distinct  distant  vision  is  pos- 
sible should  be  used.  The  question  whether  the  correcting  lenses 
should  also  be  used  for  near  objects  has  been  much  discussed.  In 
this  matter  a  general  rule  cannot  be  laid  down.  The  question 
must  be  decided  for  each  individual  case.  A  myopic  eye,  provided 
with  the  proper  concave  lens,  behaves  exactly  as  an  emmetropic 
one,  which  indeed  is  a  desirable  condition.  Nevertheless,  it  is  only 
under  the  following  circumstances  that  the  neutralizing  concave 
glasses  ought  to  be  worn  continuously  and  used  for  near  objects. 

1 .  The  myopia  should  not  be  greater  than  ^  or  ^.  For  low 
degrees  of  myopia,  under  M2^  there  is  scarcely  ever  any  neces- 
sity for  wearing  concave  glasses  continuously. 

2.  The  range  of  accommodation  must  be  normal. 

3.  Vision  must  be  normal. 

4.  The  continuous  use  of  concave  glasses  must  have  been  begun 
in  youth. 

Under  these  circumstances,  there  is  no  objection  to  the  contin- 


*  Compare  Dr.  H.  Colin,  Untersuchung  der  Augen  von  10,060  Schulkin- 
dern,  nebst  Vorschlagen  zar  Verbesserung  der  den  Augen  nachtheiligen 
Schuleinrichtungen.     Leipzig,  18G7,  und  Deutsche  Klinik,  1866,  No.  T. 


MYOPIA,  TREATMENT.  49 

uous  use  of  neutralizing  glasses.      Qne  often  sees  myopes  who 
wear  their  glasses  continuously,  and  with  only  good  effects. 

If  any  one  of  these  four  conditions  be  wanting,  we  have  a 
contra-indication  for  the  continuous  use  of  neutralizing  glasses. 
A  more  exact  explanation  of  these  conditions  belongs  with  the 
consideration  of  tlie  above-named  contra-indications.  The  cir- 
cumstances which  make  the  use  of  neutralizing  concave  lenses 
unadvisable  are  the  following : 

1.  A  high  degree  of  myopia.  The  continuous  use  of  neutral- 
izing concave  glasses  with  myopia  of  a  greater  degree  than  ^  is  un- 
advisable, on  account  of  the  diminished  acuteness  of  vision  which 
generally  co-exists.  Even  in  high  degrees  of  myopia,  where 
circumstances  make  it  necessary  to  wear  spectacles  continuously, 
the  patients  generally  prefer  those  which  do  not  completely  neu- 
tralize the  myopia.  A  continuous  use  of  such  glasses  is  sometimes 
impossible  even  for  distant  vision.  This  is  perhaps  because  of 
the  preponderating  elongation  of  the  eye  in  the  direction  of  the 
visual  axis.  The  sagittal  diameter  increases  relatively  more  than 
all  the  others,  so  that  lenses  which  correct  the  myopia  for  central 
vision  are  too  strong  for  all  objects  in  the  periphery  of  the  visual 
field.  Under  such  circumstances  it  is  often  best  to  wear  continu- 
ously spectacles  which  remove  the  far  point  to  about  12  inches,  and 
then  to  employ  an  auxiliary  glass,  about  — ^2?  ^^^  distant  vision. 

2.  Diminution  in  the  range  of  accommodation.  We  have 
already  remarked  that  the  myopic  eye  is  naturally  adapted  to 
only  slight  efforts  of  accommodation,  and  all  straining  of  accom- 
modation is  regarded  as  hurtful  to  it.  If  now  by  neutralizing 
glasses  we  remove  the  far  point  to  an  infinite  distance,  we  at  the 
same  time  remove  the  near  point  and  the  whole  range  of  accom- 
modation away  from  the  eye,  and  the  myope  who  formerly  saw 
near  objects  distinctly  without  accommodation,  can  now  do  so  only 
by  accommodating.  We  demand  in  this  case  no  more  from  the 
accommodation  than  the  emmetropic  eye  does  without  difficulty ; 
but  we  ought  first  to  satisfy  ourselves  that  the  accommodation 
of  the  myopic  eye  is  able  to  respond  to  such  a  demand  without 
injurious  straining.  We  ought,  for  instance,  never  to  compel 
continuous  accommodation  up  to  the  region  of  the  near  point. 
Myopes  who  have  worn  neutralizing  glasses  from  their  youtli,  are 
compelled  to  use  weaker  ones  on  account  of  the  gradual  with- 


50  MYOPIA,   TREATMENT. 

drawal  of  the  near  point,  dependent  upon  advancing  age.  Pres- 
byopia develops  in  myopic  as  well  as  in  emmetropic  eyes.  At 
the  same  time  of  life  when  the  erametrope  begins  to  need  convex 
glasses  the  neutralizing  concave  glasses  become  too  strong  for  the 
myope  to  use  on  near  objects. 

3.  Generally  the  use  of  concave  lenses  is  contra-indicated  if 
from  any  cause  the  acuteness  of  vision  is  noticeably  diminished. 
Corneal  opacities  or  irregular  astigmatism,  cloudiness  of  the  lens 
or  vitreous,  and  all  the  causes  of  amblyopia,  which  oc«ur  so 
frequently  in  high  degrees  of  myopia,  and  are  due  to  retinal  or 
choroidal  changes,  contra-indicate  the  use  of  concave  lenses.  For 
distance,  littlfe  is  usually  gained  by  the  correction  of  the  myopia, 
and  for  near  objects  the  hurtful  influence  of  the  concave  lenses  is 
to  be  feared,  since  the  patients,  in  spite  of  them,  approach  closely 
to  objects  in  order  to  obtain  as  large  retinal  images  as  possible, 
and  then  they  must  employ  a  tension  of  accommodation  so  much 
the  stronger.  To  abstain  as  much  as  possible  from  work  is  the 
only  advice  to  be  given  under  these  circumstances,  as  the  causes 
of  the  amblyopia  cannot  be  removed. 

4.  Finally,  with  reference  to  the  relative  range  of  accommoda- 
tion, the  use  of  concave  lenses  ought  not  to  be  begun  too  late. 
Myopes  not  only  acquire  the  habit  of  converging  to  the  near 
point  without  accommodating,  but  also  within  the  range  of  their 
distinct  vision  they  associate  with  every  degree  of  convergence 
of  the  visual  axes  only  a  relatively  slight  degree  of  accommoda- 
tion. Now,  upon  providing  the  eyes  with  concave  lenses  not 
only  is  the  entire  range  of  accommodation  removed  farther  from 
the  eye,  but  the  position  of  the  relative  range  of  accommodation 
is  also  changed.  Youthful  eyes  can  generally  accommodate  them- 
selves to  these  changed  conditions ;  or  where  this  is  the  only  dif- 
ficulty, one  can  begin  with  weak  lenses  and  proceed  gradually 
to  the  neutralizing  ones.  At  advanced  age,  however,  myopes 
cannot,  so  easily  as  emmetropes,  change  the  position  of  their  rel- 
ative range  of  accommodation.  The  greater  demand  upon  the 
available  accommodation  in  near  vision  with  concave  glasses  is 
generally  very  uncomfortable,  and  causes  quick  fatigue  of  accom- 
modation. 

It  is,  moreover,  probably  because  of  the  changed  position  in 
the  relative  range  of  accommodation  that  myopes  who  are  accus- 


MYOPIA,  TREATMENT.  51 

tomed  always  to  wear  their  neutralizing  glasses  feel  very  uncom- 
fortable so  soon  as  they  take  them  off,  even  for  near  vision. 

If  from  any  cause  the  use  of  neutralizing  glasses  cannot  be 
allowed,  we  still  often  have  occasion  to  remove  the  far  point  to  a 
given  distance,  in  order  to  allow  the  pursuit  of  some  particular  oc- 
cupation, piano-playing,  for  instance.  The  suitable  lenses  can  be 
easily  calculated.  If  we  wish  with  myopia  ^  to  remove  the  far 
point  to  18  inches,  that  is  to  reduce  this  M^  so  that  only  M^  re- 
mains, then  ^ — -i=-jlg-,  consequently  i=^.  Concave  9  is  there- 
fore the  requisite  lens.  Of  course  the  calculation  and  direct  ex- 
periment should  always  verify  each  other.  Here,  too,  the  weak- 
est lenses  which  will  fulfil  the  requirement  are  the  ones  to  be 
chosen. 

Insufficient  movement  of  the  eyes  in  consequence  of  their 
change  of  form  exists  generally  only  in  high  degrees  of  myopia. 
It  appears  best  that  the  relative  divergence  in  near  vision  which 
results  from  it  should  not  be  interfered  with.  Under  these  cir- 
cumstances little  is  to  be  accomplished  with  the  prismatic  spectacles 
which  are  so  often  employed.  The  optical  effects  of  prisms  will 
be  more  particularly  explained  hereafter. 

If,  on  the  contrary,  the  difficulty  of  binocular  vision  does  not 
depend  upon  a  limitation  of  the  movement  of  the  eyes  but  upon 
an  elastic  preponderance  of  the  external  recti  muscles,  and  if  it 
is  evident  that  binocular  vision  can  be  maintained  only  by  a  strain 
upon  the  internal  recti  muscles,  the  indications  are  for  a  tenotomy 
of  the  rectus  externus.  This  condition  occurs  congenitally,  as 
does  myopia;  it  is  often  a  complication  of  slight  degrees  of 
myopia. 

The  symptoms  of  irritation  which  frequently  appear  at  the 
period  of  puberty,  characterized  by  hypertemia  of  the  optic  nerve, 
quick  fatigue  and  pain  in  the  eyes,  especially  when  working  in 
the  evening,  demand  a  strict  hygienic  regimen.  There  must  be 
good  light,  frequent  interruption  of  work,  the  head  must  not  be 
bent  forward,  all  influences  which  tend  to  congestion  of  the  head 
or  eyes  must  be  avoided,  the  feet  must  be  kept  warm,  the  bowels 
open,  the  douche  must  be  used  with  closed  lids  and  sometimes 
blood  is  to  be  drawn  with  the  artificial  leech.  In  slight  degrees 
of  myopia  it  is  advisable  under  these  circumstances  to  avoid 
the  use  of  spectacles ;  in  high  degrees,  if  the  difficulties  are  not 


52  MYOPIA,  TEEATMENT. 

thereby  increased,  the  far  point  may  be  removed  by  concave 
glasses  to  about  12  inches;  all  strong  convergence  is  to  be  avoided. 
If  we  suspect,  as  is  frequent  in  high  degrees  of  myopia  in  young 
individuals,  that  the  symptoms  of  irritation  are  caused  by  spasm 
of  the  muscle  of  accommodation,  the  spasm  is  first  to  be  relieved 
by  the  use  of  atropine,  and  the  true  degree  of  the  myopia  is 
then  to  be  determined ;  the  use  of  atropine  can  be  continued 
several  days,  during  which  time  the  eyes  should  be  protected 
from  dazzling  light  by  colored  glasses.  Upon  a  recurrence  of 
the  spasm  of  accommodation  the  use  of  the  artificial  leech  is 
advisable. 

The  cases  of  diminished  acuteness  of  vision  which  develop  in 
the  course  of  myoi)ia,  and  which  depend  upon  diseases  of  the 
vitreous,  retina,  or  choroid,  require  a  derivative  treatment,  and 
such  eyes  must  be  spared  as  much  as  possible. 

The  prognosis  in  these  cases  is,  on  an  average,  so  much  the 
better  the  fewer  the  material  changes  visible  with  the  ophthalmo- 
scope. 

HYPERMETROPIA. 

Hypermetropia  exists  when,  accommodation  being  relaxed,  par- 
allel rays  falling  upon  the  cornea  of  the  eye  are  focused  at  a  point 
behind  the  retina.  Under  these  circumstances  every  luminous 
point  casts  a  circle  of  diffusion  upon  the  retina.  It  is  only  by 
an  effort  of  accommodation,  or  (since  we  are  at  present  not  regard- 
ing accommodation,  but  considering  only  the  condition  of  refrac- 
tion) by  the  help  of  convex  lenses,  that  the  image  of  the  luminous 
point  can  be  brought  forward  and  cast  upon  the  surface  of  the 
retina.  In  a  hypermetropic  eye,  whose  accommodation  is  fully 
relaxed,  it  is  only  rays  already  converging  which,  falling  upon 
the  cornea,  are  united  upon  the  retina.  The  point  behind  the  eye 
toward  which  they  converge  is  called  the  far  point.  Of  course 
only  a  convex  lens  of  a  certain  focal  length  can  give  to  parallel 
rays  such  a  convergence  as  is  necessary  to  cast  an  image  from  dis- 
tant objects  exactly  upon  the  retina ;  this  can  hajipen  only  when 
the  focal  point  of  the  lens  and  the  far  point  of  the  eye  coincide. 
Such  a  lens  is  called  the  neutralizing  one ;  it  expresses  the  grade 
of  the  hypermetropia.  Strictly  speaking,  the  distance  between 
the  lens  and  the  eye  must  be  taken  into  account  just  as  in  myopia. 
If  for  instance  the  rays  must  converge  toward  a  point  12  inches 


HYPERMETROPIA.  53 

behind  the  cornea  in  order  to  be  focused  upon  the  retina,  then  the 
far  point  lies  12  inches  behind  the  eye,  and  hypermetropia  of  -^ 
exists  (H  -^). 

The  condition  of  refraction  in  the  hypermetropic  eye  is  such 
that  it  is  adjusted  for  converging  rays.  Now,  since  we  generally 
have  to  do  only  with  diverging  or  parallel  rays,  it  is  evident  that 
the  hypermetropic  eye  possesses  a  useless  faculty,  and  one  which 
often  leads  to  unpleasant  consequences. 

Absolute  hypermetropia  exists  when  with  its  greatest  power  of 
accommodation  the  eye  cannot  adjust  itself  for  parallel  light,  but 
only  for  rays  which  converge  toward  a  point  behind  and  more  or 
less  distant  from  it.  The  whole  range  of  its  accommodation  from 
its  far  to  its  near  point  lies  beyond  infinity.  Distinct  vision  even 
for  distance  is  consequently  impossible  without  a  convex  lens. 

With  relative  hypermetropia  the  eye  can  adjust  itself  for  paral- 
lel or  even  diverging  light,  but  it  can  do  so  only  when  at  the  same 
time  the  visual  axes  converge  upon  a  distance  Avhich  is  less  than 
that  upon  which  accommodation  is  adjusted. 

With  facultative  hypermetropia  the  binocular  near  point  lies  at 
a  finite  distance;  distinct  distant  vision  with  parallel  visual  axes  is 
also  possible ;  so  is  near  vision  with  a  proper  convergence  of  the 
visual  axes;  there  is,  however,  distinct  distant  vision  and,  of 
course,  near  vision  also,  when  convex  lenses  are  used. 

The  above  classification  depends  not  only  upon  the  grade  of 
the  hypermetropia,  but  upon  the  range  of  accommodation.  If 
the  degree — that  is,  the  optical  value  of  the  hypermetropia — is 
higher  than  that  of  the  range  of  accommodation,  the  hypermetropia 
M'ill  always  be  absolute.  The  gradual  narrowing  of  the  range  of 
accommodation  which  occurs  with  increasing  years  makes  an  origi- 
nally facultative  hypermetropia  finally  an  absolute  one;  and,  on 
the  other  hand,  most  cases  of  hypermetropia  at  a  youthful  age,  with 
ample  range  of  accommodation,  are  facultative. 

Donders  has  represented  diagrammatically  the  relations  in  hy- 
permetropia, upon  the  same  plan  as  he  has  those  of  the  relative 
range  of  accommodation  (see  page  20).  To  do  this  it  is  only  neces- 
sary to  represent  that  part  of  the  range  of  accommodation  lying 
beyond  an  infinite  distance  by  horizontal  lines  whose  respective 
distances  from  one  another  represent  an  optical  value  of  2^ ;  these 
follow  in  order  under  the  line  marked  cc. 


54 


H  YPERMETEOPI A . 


Fig.  10  represents  the  facultative  hypermetropia  and  range  of 
accommodation  of  a  man  28  years  old,  whose  manifest  hyperme- 
tropia is  corrected  by  convex  30,  whose  far  point,  therefore,  lies 
30  inches  behind  his  eye.  The  relative  near  point  with  parallel 
axes  of  vision-  is  20  inches  in  front  of  the  eye ;  he  sees  at  a  dis- 
tance as  well  with  4-3V  ^^  '^^'^^^  — To"-  '^^^  relative  range  of 
accommodation  with  parallel  visual  axes  is  then  yo -\- ■^'=y2- 


1:2 
9  2 

•?2 


33 

4 

4| 
6 
8 
12 
24 
00 

24 
12 


Fig.  10. 


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/ 

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/ 

/ 

/ 

/ 

V 

, 

^___ 

^p 

r-- 

— -*■ 

^ 

f 

^/^ 

\ 

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trx/ 

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^^ 

11°2F    22°50^     34°32^    46°38'     59°20':     72°50' 


At  a  distance  of  lOJ  inches  he  can  for  a  short  time  see  bin- 
ocularly.  In  the  course  of  years,  however,  the  range  of  accommo- 
dation will  become  narrowed  by  the  withdrawal  of  the  near  point, 
so  that  before  his  thirty-eighth  year  his  facultative  hypermetropia 
will  become  relative,  and  about  his  forty-fifth  year  absolute. 

In  Fig.  11,  JJ  shows  the  relative  hypermetropia  of  a  girl  of  17 
years.  The  manifest  far  point  r^m  lies  about  7  inches  behind  the 
eye  (convex  7  corrects  the  hypermetropia).  The  absolute  near 
point  lies  10  inches  from  the  eye;  if  one  assumes  in  the  calcula- 


HYPEEMETEOPIA. 


55 


tion  of  the  range  of  accommodation  7-^m  as  the  far  point,  we  have 
A^T^,  ^"cl  still  the  near-point  line  2^^  P^  P  "ever  reaches  the 
diagonal  K  K',  which  represents  the  convergence  of  the  visual 
axes. 

Fig.  11. 
1:2 

2-?- 
3 

^ 
4 

H 

6 


12 
24 

00 

1:24 

12 

8 

6 
4-i 

4 
8f 

3 

22 

^0°   11°21^  22°50^  34°82^  46°88^  59°20^  72°50^ 


/ 

p^ 

/ 

y 

/ 

— 

-- 

- — 

/ 

/ 

/ 

/ 

J 

p' 

V 

0 

^■^ 

i — ^ 

Y^ 

/ 

7 

^ 

/ 

E 

r^ 

^' 

^ 

7 

^ 

^ 

^ 

^ 

7 

p 

/ 

^ 

\y 

/ 

/ 

fV 

/ 

,^ 

y 

^ 

y 

Y 
?'.' 

[y 

^ 

I 

J 

/ 

*^' 

y 

^^ 

'■■in 

/ 

f^ 

/ 

/ 

/ 

/ 

■m 

This  eye  can  accommodate  for  divergent  light,  but  can  do  so 
only  when  the  visual  axes  intersect  at  a  point  which  is  nearer  the 
eye  than  the  point  upon  which  the  accommodation  is  adjusted. 
The  hypermetropia  is  not  absolute,  but  it  is  so  in  relation  to  the 
convergence  of  the  visual  axes.  For  instance,  accommodation 
can  be  adjusted  for  a  distance  of  16  inches,  but  only  by  con- 


56  HYPERMETROPIA. 

verging  at  the  same  time  for  a  distance  of  12  inches,  or  under  an 
angle  of  convergence  of  10°  21'.  This  particular  patient,  how- 
ever, does  not  avail  herself  of  this  possibility,  even  when  one  eye  is 
covered.  Consequently,  she  does  not  see  distinctly  with  the  naked 
eye  at  any  distance,  not  even  raonocularly ;  she  can  see  well,  how- 
ever, with  convex  lenses.  Perhaps  at  the  age  of  11  or  12  years, 
when  the  range  of  accommodation  was  greater,  she  could  see 
distinctly  even  binocularly.  When,  with  increase  of  years,  her 
accommodation  shall  be  reduced  to  y,  her  relative  hypermetropia 
will  become  absolute. 

The  lines  Jin  Fig.  11  show  the  limits  of  accommodation  in  a 
case  of  very  high  degree  of  hypermetropia.  Nearly  H^  exists, 
and  yet  by  the  help  of  strong  convergence  the  eyes  can  be  adjusted 
almost  for  parallel  rays.  The  range  of  accommodation  is  about 
^ ;  some  years  earlier  it  was  probably  greater,  and  the  hyperme- 
tropia was  then  not  yet  absolute. 

In  facultative  hypermetropia,  with  normal  acuteness  of  vision, 
distant  vision  is  possible,  but  only  by  a  tension  of  accommodation 
corresponding  to  the  grade  of  the  hypermetropia.  If  for  instance 
in  hypermetropia  -^  there  be  accommodation  I,  the  patient  can 
indeed  see  plainly  at  a  distance,  but  only  by  an  eflPort  of  accom- 
modation which  adjusts  the  eye  for  parallel  rays.  The  accommo- 
dation does  exactly  what  a  convex  glass  of  12  inches  focal  distance 
would  have  done;  x=tt  '^^  employed;  of  course  there  remain  -^ 
=  1, — that  is,  the  near  point  can  be  brought  only  up  to  6  inches. 
The  entire  range  of  accommodation  is  further  removed  from  the 
eye. 

While  the  emmetrope  with  parallel  visual  axes,  and  with  full 
relaxation  of  accommodation,  can  see  distinctly  at  a  distance,  the 
hypermetrope,  under  these  circumstances,  must  accommodate  ac- 
cording to  the  condition  of  his  refraction ;  he  must  accommodate 
still  more  for  near  objects.  Under  all  circumstances,  in  obtaining 
distinct  retinal  images  hypermetropes  make  greater  demands  on 
their  accommodation  than  do  emmetropes,  and  for  that  reason 
there  develops  a  permanent  tension  of  the  muscle  of  accommoda- 
tion, independent  of  the  will,  so  that  accommodation  can  no  longer 
be  voluntarily  relaxed. 

This  renders  it  difficult  to  determine  exactly  the  degree  of  the 
hypermetropia.     We  have  already  said  that  this  degree  of  hyper- 


HYPERMETROPIA.  57 

metropia  is  expressed  by  that  convex  lens  which,  in  the  relaxed 
eye,  focuses  parallel  rays  upon  the  retina.  But  it  is  only  with 
full  relaxation  of  the  accommodation  that  the  focal  length  of  that 
convex  lens  which  gives  distinct  distant  vision  expresses  the 
degree  of  the  hypermetropia.  Every  tension  of  accommodation, 
during  the  examination,  acts  in  the  same  sense  as  a  convex  lens, 
and  from  this  follows  the  rule,  that  the  strongest  convex  lens  with 
which  distinct  distant  vision  is  possible  is  the  one  which  expresses 
most  correctly  the  degree  of  the  hypermetropia.  Now,  in  many 
cases  a  full  relaxation  of  accommodation  never  occurs,  so  that 
distinct  distant  vision  is  possible,  sometimes  with  a  stronger,  some- 
times with  a  weaker,  convex  lens.  The  grade  of  the  hyperme- 
tropia, which  is  expressed  by  the  strongest  convex  lens  with  which 
distinct  vision  is  possible,  is  called,  under  these  circumstances, 
manifest  hypermetropia  (Hm) ;  the  actual  or  absolute  degree 
can  be  discovered  only  by  first  paralyzing  the  accommodation. 
The  interval  between  the  manifest  and  the  absolute  far  point  is 
called  "  latent  hypermetropia"  (HI),  or  "  latent  range  of  accom- 
modation." 

Very  striking,  and  indicative  of  the  force  of  habit,  is  the  fact 
that,  after  complete  atropine  mydriasis,  the  latent  hypermetropia 
returns,  even  when  the  patient  wears  continuously  those  convex 
glasses  with  which  there  is  distinct  vision  during  the  paralysis  of 
accommodation.  In  proportion  as  the  range  of  accommodation, 
subject  to  the  will,  again  develoj^s,  there  occurs  again  the  spasm 
of  accommodation,  which  is  directly  opposed  to  the  interests  of 
vision,  which  now  is  less  distinct  with  convex  lenses  than  with 
the  naked  eye. 

Another  consequence  of  the  strong  tension  of  accommodation' 
which  hypermetropes  must  make  in  order  to  see  distinctly,  appears 
in  the  behavior  of  the  relative  range  of  accommodation.  While 
with  the  ordinary  convergence  of  the  visual  axes  necessary  for 
work  the  myope  uses  only  a  little,  and  the  emmetrope  perhaps 
half,  of  his  available  range  of  accommodation,  the  hypermetrope 
uses  nearly  all  of  it.  This  demand  sometimes  exceeds  the  strength 
of  the  muscle  of  accommodation;  it  refuses  to  do  its  duty,  and  in 
this  way  are  developed  those  difficulties  which  are  known  by  the 
name  of  asthenopia. 

Of  the  troubles  connected  with  hypermetropia,  asthenopia  is 

5 


58  HYPEEMETROPlA. 

the  principal  one.  Its  symptoms  are  very  characteristic,  and  the 
disease  is  one  long  known  and  described  under  the  greatest  variety 
of  names,  such  as  hebetudo  visus,  kopiopie,  amblyopic  presbytique, 
impaired  vision  from  overwork,  etc.  It  was  never  rightly  under- 
stood till  Donders  showed  hypermetropia  to  be  the  true  cause  of  it. 

Upon  external  examination,  the  eyes  show  no  anomaly;  the 
acuteness  of  vision  is  generally  normal ;  when  work,  such  as 
writing,  reading,  sewing,  etc.,  is  undertaken,  vision  is  at  first  dis- 
tinct, but  soon,  especially  by  artificial  or  imperfect  light,  vision 
becomes  indistinct  and  confused;  a  feeling  of  fatigue  and  tension  is 
experienced,  especially  above  the  eyes ;  it  becomes  necessary  to  sus- 
pend work  ;  the  eyes  are  shut,  the  forehead  and  eyelids  are  rubbed 
with  the  hand,  and  after  a  short  rest  work  can  be  again  resumed. 
Soon,  however,  the'same  inconveniences  recur.  The  interruptions 
become  more  frequent,  and  must  be  more  and  more  prolonged ; 
finally,  the  work  must  be  entirely  abandoned.  If,  in  spite  of  the 
strain  upon  the  eyes,  work  be  continued,  the  feeling  of  tension 
above  the  eyes  becomes  one  of  actual  pain,  the  eyes  become  red 
and  filled  with  tears,  and  for  a  short  time  even  distant  vision  is 
imperfect.  Pain  in  the  eyes  themselves  is  rare  in  accommodative 
xisthenopia. 

The  higher  the  degree  of  the  hypermetropia  the  earlier  the  age 
at  which  accommodative  asthenopia  appears.  In  the  middle  grades 
of  hypermetropia  it  develops  later,  and  it  may  happen  that  the  hy- 
permetropia is  completely  masked,  up  to  the  limit  of  the  far  point, 
so  that  the  entire  hypermetropia  remains  latent,  while  the  effort 
of  accommodating  to  almost  the  near  point  is  so  great  that  it  can 
be  maintained  only  for  a  short  time. 

*  Slight  hypermetropia  may  exist  a  long  time  Avithout  causing  any 
inconvenience.  The  eyes  gradually  accustom  themselves  to  com- 
bining with  every  convergence  of  the  visual  axes,  a  relatively 
strong  strain  of  the  accommodation,  and  to  maintain  the  same 
while  working.  But  as,  in  the  course  of  years,  by  the  gradual 
withdrawal  of  the  near  point,  the  absolute  extent  of  the  range  of 
accommodation  becomes  lessened,  just  so,  finally,  does  the  relative 
available  tension  of  accommodation,  corresponding  to  the  degree 
of  convergence  necessary  for  work,  become  too  small.  Fatigue 
comes  on  sooner  and  sooner.  In  this  way  slight  hypermetropia 
leads  to  pi'emature  presbyopia,  more  likely  to  be  complicated  with 


IIYI'ER^fETROPIA.  59 

asthenopic  difficulties,  and  occurring  earlier  in  life  the  higher 
the  grade  of  the  hypermetropia.  Of  course,  the  occurrence  of 
asthenopic  difficulties  is  favored  by  all  debilitating  influences 
which  weaken  the  energy  of  the  muscular  system  in  general  and 
the  ciliary  muscle  in  particular.  Indeed,  after  prostrating  sick- 
nesses, after  severe  hemorrhages,  or  with  paresis  of  accommoda- 
tion, asthenopic  difficulties  may  occur  without  the  existence  of 
any  hypermetropia. 

The  principal  symptom  of  absolute  hypermetropia  is  indistinct 
vision  of  both  near  and  far  objects,  and  in  such  a  condition  one 
of  the  most  j)rom incut  features  in  asthenopia  is  wanting,  namely, 
distinct  vision  at  first. 

There  often  exist  simultaneously  with  hypermetropia,  especially 
in  connection  with  the  higher  grades  of  it,  other  causes  for  de- 
fective vision,  such  as  astigmatism,  or  meridional  asymmetry ;  not 
un frequently  there  is  amblyopia,  for  which  there  exists  no  discov- 
erable cause,  and  which,  therefore,  must  be  considered  as  amblyopia 
congenita. 

A  very  characteristic  symptom,  under  these  circumstances,  is, 
that  such  patients  hold  objects  which  they  wish  to  see  distinctly, 
for  instance,  the  book,  when  reading,  as  near  as  possible  to  the 
eye ;  they  may  even  use  an  object  distance  of  from  1  to  2  inches. 
When  this  is  done,  as  Von  Graefe*  has  shown,  the  size  of  the 
retinal  images  increases  more  rapidly  than  that  of  the  circles  of 
diffusion.  Moreover,  as  Donders  remarks,  it  is  probably  in  these 
cases  more  a  question  of  monocular  polyopia  than  of  circles  of 
diffusion.  Some  of  the  multiple  images  can  be  excluded  by  par- 
tially closing  the  lids,  or  in  monocular  vision,  by  holding  the  book 
on  one  side,  so  that  the  nose  covers  a  part  of  the  pupil ;  both  these 
devices  are  practised  with  so  much  the  happier  effect  the  smaller 
the  pupil.  If  under  these  circumstances  even  fine  print,  for  in- 
stance, No.  I  of  the  usual  test  letters,  can  be  read  at  a  distance  of 
1  inch,  this  would  indicate  an  acuteness  of  vision  of  only  about 
Y^,  for  the  retinal  images  must  be  very  indistinct.  Such  patients, 
by  practice,  have  learned  to  draw,  from  very  imperfect  retinal 
images,  correct  conclusions  as  to  the  form  of  objects. 

The  anatomical  peculiarity  of  the  hypermetropic  eye  is,  that  all 

*  Arch.  f.  Ophth.,  ii.  1,  pag.  181 


60  HYPERMETROPIA. 

its  diameters,  and  particularly  its  sagittal  diameter,  are  shorter 
than  in  emmetropic  eyes.  This  shortness  of  the  axis  is  probably 
the  cause  of  the  hypermetropia ;  at  least  there  are  no  discoverable 
changes  in  the  refracting  media  which  could  increase  the  focal 
distance.  Ophthalmometric  measurement  has  shown  that  the 
cornea  is  not  flatter ;  ])ut  in  high  grades  of  hypermetropia,  where 
its  circumference  is  smaller  than  normal,  its  curvature  is  generally 
even  greater  than  in  the  emmetropic  eye.  The  reason,  that  it  ap- 
pears flatter  is,  just  as  in  presbyopia,  because  the  anterior  chamber 
is  shallower  and  the  pupil  smaller.  AVhether  in  hypermetropic 
eyes  the  lens  is  flatter  than  usual  is  not  known. 

A  further,  and  often  very  striking,  peculiarity  is,  that  in  hyper- 
metropia the  line  of  vision  deviates  inward  from  the  centre  of 
the  cornea  much  more  than  in  emmetropia  (comp.  p.  42).  AVith 
parallel  visual  axes,  perpendiculars  let  fall  upon  the  centre  of  the 
cornea  would  therefore  diverge  strongly,  causing  an  apparent  stra- 
bismus divergens,  concerning  which  we  have  yet  to  speak  more 

fully. 

The  hypermetropic  formation  of  the  eye  occurs  congenitally.  E. 
von  Jaeger,*  by  opththalmoscopic  examination  of  the  condition  of 
refraction,  found  hypermetropia  in  17  cases  among  100  new-born 
infants.  Hypermetropia  may  also  develop  during  the  growth  of 
the  eye.  A  hereditary  influence  is  very  evident.  If  parents  have 
hypermetropia,  it  is  generally  observed  in  some  of  their  children 
also.  On  the  other  hand,  several  brothers  and  sisters  may  be 
hypermetropic  when  the  same  anomaly  did  not  exist  in  the  parents. 

It  is  only  relatively  seldom  that  hypermetropia  is  acquired. 
The  removal  of  the  lens  from  behind  the  pupil  (aphakia)  is  the 
most  frequent  cduse  of  acquired  hypermetropia. 

Glaucoma  in  its  early  stages  may  also  perhaps  cause  hyjierrae- 
tropia.  The  flattening  of  the  cornea  by  central  facets  may  cause 
a  high  degree  of  hypermetropia  complicated  by  irregular  astig- 
matism. Finally,  a  displacement  forward  of  the  retina  by  cho- 
roidal exudations,  or  a  flattening  of  the  posterior  part  of  the  eye 
by  orbital  tumors,  may  cause  hypermetropia. 

The  existence  of  hypermetropia  is  proved  whenever  with  normal 
or  nearly  normal  acuteness  of  vision  the  patient  sees  at  a  distance 

*  Einstellungen  des  dioptriscben  Apparates,  pag.  20. 


HYPERMETROPIA.  61 

as  well  with  convex  lenses  as  Avith  the  naked  eye.  Where  the 
acuteness  of  vision  is  considerably  less  than  normal,  this  method  of 
examination  is  unreliable,  because  the  enlargement  of  the  retinal 
images  caused  by  the  convex  lenses  may  improve  vision  without 
the  presence  of  hypermetropia.  In  such  cases  the  ophthalmoscopic 
diagnosis  should  be  made ;  this  will  be  explained  later. 

In  cases  of  hypermetropia  complicated  wdth  amblyopia,  espe- 
cially when  both  anomalies  exist  in  a  somewhat  hig-h  decree, 
there  is  often  no  result  attained  by  the  examination  with  convex 
lenses  and  test  letters.  The  patients  say  they  see  better  sometimes 
with,  sometimes  without,  sometimes  with  weaker,  sometimes  with 
stronger,  lenses.  The  reason  for  these  contradictory  statements  is, 
that  even  hypermetropes  with  good  vision  are  compelled  to  accom- 
modate whenever  they  wish  to  see  anything  distinctly,  and  the 
necessity  so  to  do  is  still  greater  when  there  is  amblyopia.  This 
acquired  habit  of  straining  the  accommodation  for  the  sake  of 
distinct  vision  is  not  avoided  during  an  examination  with  convex 
lenses;  consequently  it  is  impossible  to  attain  an  accurate  result. 
In  the  ophthalmoscopic  examination,  on  the  contrary,  the  patient 
has  no  necessity,  and  scarcely  the  possibility,  of  distinct  vision ; 
he  relaxes  his  accommodation,  and  then  with  the  ophthalmoscope 
we  can  determine  the  existence  of  the  anomaly  of  refraction  with 
certainty,  and  generally,  too,  its  degree  with  sufficient  exactness. 
By  reason  of  a  permanent  tension  of  the  accommodation,  a  part 
of  the  hypermetropia  may  remain  latent,  even  during  the  oph- 
thalmoscopic examination. 

Even  with  good  vision  a  latent  tension  of  accommodation  may 
render  the  diagnosis  difficult.  In  such  cases  the  only  method  by 
which  to  ascertain  the  existence  of  hypermetropia,  and  determine 
the  grade  of  it,  is  to  paralyze  temporarily  the  accommodation  by 
atropine. 

Hypermetropes  generally  seek  treatment  either  on  account  of 
accommodative  asthenopia  or  for  indistinctness  of  vision.  Both 
difficulties  may  occur  very  early  in  high  degrees  of  hypermetropia. 

The  relief  of  asthenopia  is  no  longer  difficult,  since  Donders 
has  so  successfully  combated  the  error  which  would  forbid  the 
use  of  strong  convex  glasses  to  young  persons. 

If  in  connection  with  accommodative  asthenopia  the  usual 
manifest  hypermetropia  exist,  it  generally  suffices  to  correct  this ; 


62  HYPERMETROPIA. 

that  is,  to  order  the  strongest  convex  lenses  with  which,  during 
the  examination,  distinct  distant  vision  is  possible.  Such  glasses 
generally  relieve  the  asthenopic  difficulties  immediately.  It  may 
happen  that  glasses  which  correct  simply  the  manifest  hyperme- 
tropia  nevertheless  appear  to  the  patient  to  be  too  strong;  the 
work  must  be  brought  nearer  the  eye  than  usual,  so  that  an  un- 
wonted convergence  of  the  visual  axes  is  required ;  the  objects 
appear  distinct,  it  is  true,  but  unpleasantly  magnified,  etc. 
Chiefly  is  this  the  case  with  such  hyperraetropes  as  have  long 
been  accustomed  to  Avork  without  any  or  with  too  weak  convex 
glasses,  and  have  thereby  acquired  the  habit  of  combining  the 
convergence  of  the  visual  axes  necessary  to  their  pursuits  with  a 
relatively  strong  tension  of  accommodation  ;  they  cannot  give  up 
the  habit  even  when  properly-chosen  convex  glasses  render  accom- 
modation necessary.  Under  these  circumstances,  somewhat  weaker 
glasses  generally  relieve  all  difficulties. 

On  the  other  hand,  it  may  haj)pen  that  the  correction  of  the 
manifest  hypermetropia  is  not  sufficient,  and  that  for  entire  relief 
of  the  asthenopic  symptoms  stronger  convex  glasses  are  necessary. 
Of  course  this  is  always  the  case  when  the  range  of  accommoda- 
tion is  diminished  by  the  development  of  presbyopia. 

If  the  difficulties  of  accommodative  asthenopia  exist  while 
there  is  no  manifest  hypermetropia,  or  only  a  very  slight  degree 
of  it,  there  is  no  course  left  but  to  paralyze  accommodation  by 
atropine,  and  then  to  determine  if  hypermetropia  exist,  and  if  so, 
in  what  degree.  It  is  advisable,  however,  to  limit  the  use  of  atro- 
pine as  much  as  possible,  since  its  effects,  when  applied  in  sufficient 
quantities  to  produce  absolute  paralysis  of  the  muscle  of  accom- 
modation, last  several  days,  and  during  this  time  the  patient  is 
in  a  very  uncomfortable  condition.  If  latent  hypermetropia  be 
found,  then  would  the  neutralizing  convex  glass  be,  as  a  rule,  too 
strong ;  it  is  advisable  to  neutralize,  then,  only  the  manifest  and 
perhaps  I  of  the  latent  hypermetropia.  If,  as  rarely  happens, 
the  asthenopic  symptoms  do  not  yield,  in  spite  of  properly-chosen 
convex  glasses,  we  must  look  for  other  co-existing  affections  which 
might  cause  similar  troubles,  for  instance,  astigmatism,  muscular, 
conjunctival,  or  nervous  asthenopia. 

So  long  as  in  facultative  hypermetropia  the  accommodation  is 
sufficient  to  give  distinct  distant  vision,  it  is  not  advisable  to  allow 


HYPERMETROPIA.  63 

the  use  of  convex  lenses  continuously,  and  for  distance.  Other- 
wise the  time  will  soon  come  when  the  correcting  convex  lenses, 
with  which  distant  vision  is  good,  will  not  be  strong  enough  for 
near  objects.  In  absolute  hypermetropia,  on  the  other  hand, 
whether  it  appear  in  early  youth  or  is  developed  in  consequence 
of  presbyopia,  from  hypermetropia  that  was  originally  facultative, 
correcting  convex  glasses  may  be  worn  continuously.  In  young 
})eople,  such  glasses  are  generally  sufficient  for  all  purposes,  while 
later  in  life,  for  near  vision,  it  becomes  necessary  to  wear  glasses 
which  correct  the  hypermetropia  and  the  presbyopia  as  well. 

The  relation  between  hypermetropia  and  strabismus  convergens 
will  be  discussed  under  the  title  "  diseases  of  the  ocular  muscles." 


ASTIGMATISM. 

We  have  shown  that  in  the  normal  emmetropic  condition  of 
refraction,  rays  of  light  which  fall  parallel  upon  the  cornea,  with 
absolute  rest  of  accommodation,  are,  after  refraction,  focused 
exactly  upon  the  retina. 

If  the  place  of  the  image  cast  by  a  distant  luminous  point  h& 
not  upon  the  retina,  it  must  be  either  before  or  behind  it,  and 
looked  at  from  this  point  of  view  there  seem  to  be  but  two  anoma- 
lies of  refraction  possible,  viz.,  myopia  and  hypermetropia.  There 
is,  however,  a  third,  dependent  upon  the  fact  that  rays  of  light 
proceeding  from  a  given  point  (homocentric  light)  do  not  in  gen- 
eral, after  their  refraction  in  the  eye,  remain  homocentric,  Ety» 
mologically,  the  word  astigmatism  expresses  nothing  more  than 
that  condition  in  which  homocentrio  rays,  softer  their  refraction  in 
the  eye,  do  not  intersect  each  other  again  in  one  and  the  same 
point.  The  fact  that  to  most  men  the  stars  do  not  appear  as  round 
dots,  but  star-shaped,  proves  the  frequency  of  these  aberrations, 

In  fact,  the  human  eye  shows  the  same  defects  which  we  seek 
to  correct  in  an  optical  instrument,  or  which  net  being  corrected  we 
would  regard  as  a  fault.  These  aberrations  exist  too  in  a  quite  high 
degree.  Chromatic  aberration  is  least  noticeable,  although  the  eye 
is  by  no  means  free  from  it ;  under  ordinary  circumst^vnoes  it  does 
not  affect  the  acuteness  of  vision,  The  monochromatic  aberra- 
tions of  the  eye  are  more  important,  and  are  complicated  to  a  high 
degree,     For  our  present  purpose  we  must  distinguish  between 


64 


ASTIGMATISM. 


(a)  An  aberration  affecting  those  raya  which  are  refracted  in 
one  and  the  same  meridian,  and 

(6)  An  aberration  dependent  upon  differences  in  the  focal  length 
of  the  various  meridians  of  the  refracting  apparatus. 

The  first,  which  is  called  irregular  astigmatism,  depends,  under 
physiological  relations,  partly  upon  the  form  of  the  cornea,  but 
mostly  upon  irregularity  of  refraction  in  the  lens.  In  the  first 
place,  its  curved  surfaces  are  not  centred  with  those  of  the  cornea ; 
further,  the  refraction  in  the  various  sectors  of  the  lens  varies,  so 
that  each  sector  casts  an  image  which  does  not  coincide  with  that 
of  the  sector  lying  opposite  and  on  the  same  meridian  with  it,  and 
finally,  each  image  of  each  sector  possesses  an  aberration  of  its  own.* 
Under  pathological  conditions  irregular  astigmatism  is  oftenest 
caused  by  cloudiness  of  the  cornea  and  partial  cloudiness  of  the  lens. 
The  aberration  depending  upon  inequality  of  the  dioptric  appa- 
ratus, in  its  different  meridians,  is  called  regular  astigmatism,  or 
meridional  asymmetry. 

It  appears  to  be  only  seldom  that  meridional  asymmetry  is 
absent.  The  near  point  of  most  eyes  lies  nearer 
for  horizontal  than  for  vertical  lines,  and  the  same 
symptom  can  also  be  shown  for  the  far  point,  if 
when  myopia  is  not  already  present,  the  far  point 
be  brought  nearer  by  means  of  a  carefully-centred 
convex  glass. 

The  physiological  meridional  asymmetry  of  the 
cornea  has  been  demonstrated  objectively  by  oph- 
thalmometric  measux'ement.  In  the  majority  of 
cases  the  vertical  meridian  was  shown  to  have  a 
shorter  radius  of  curvature  than  the  horizontal, 
although  the  principal  meridians — that  is,  those 
liaviug  the  greatest  and  least  curvature—do  not  by 
any  means  stand  always  in  a  vertical  and  hori- 
zontal position.  The  manner  in  which  light  is 
refracted  by  such  asymmetric  surfaces  was  long 
ago  investigated  by  Sturm.  He  found  (comp. 
Fig.  12)  that  a  homocentric  beam  of  light,  after 
refraction  by  an  asymmetric  surface,  is  not  united  at  a  focal  point, 

*  Donders,  Astigmatismus  und  cylindrische  Gliiser,  Berlin,  1862,  pag.  9, 


I 


ASTIGMATISM.  65 

but  experiences  its  greatest  concentration  within  a  certain  interval, 
which  is  called  the  "  focal  interval ;"  this  interval  is  bounded  by 
two  lines,  the  anterior  (Ji  h')  and  posterior  {v  v')  focal  lines,  which 
include  all  the  rays. 

The  place  of  the  anterior  focal  line  is  determined  by  the  focal 
distance  of  the  meridian  of  greatest  ( F),  and  its  direction  by  the 
direction  of  the  meridian  of  least  (H),  curvature.  A  circle  of  dif- 
fusion is  formed  at  the  middle  of  the  focal  interval.  The  posterior 
focal  line  stands  at  right  angles  with  the  anterior  one ;  its  place 
is  determined  by  the  focal  distance  of  the  meridian  of  least  curva- 
ture; its  direction  is  in  the  plane  of  the  meridian  of  greatest 
curvature. 

The  greater  the  asymmetry,  the  longer  the  focal  interval,  and 
the  longer  the  focal  lines  which  bound  it. 

We  can  now  easily  understand  the  different  adjustment  of  the 
eye  for  horizontal  and  vertical  lines.  If,  for  instance,  the  meridian 
of  shortest  focal  distance  be  vertical,  and  that  of  longest  focal  dis- 
tance horizontal,  then  will  the  anterior  focal  line  have  a  horizontal, 
and  the  posterior  a  vertical,  direction. 

A  horizontal  line  whose  retinal  image  coincides  with  the  anterior 
focal  line  will  appear  perfectly  distinct,  except  at  each  end,  for  a 
distance  equal  to  half  the  length  of  the  diffuse  image  thrown  from 
each  and  every  individual  point  of  the  line,  since  the  diffuse  images 
from  all  its  points  are  again  horizontal  lines  which  overlap  each 
other.  A  vertical  line  at  the  same  distance  will,  on  the  contrary, 
appear  broad  and  indistinct,  because  each  of  its  points  casts  a 
horizontal  diffuse  image;  the  vertical  line  can  cast  a  distinct 
image  only  by  such  an  effort  of  accommodation  as  is  necessary  to 
bring  the  posterior  focal  line  upon  the  retina.  Of  course,  in  that 
case,  the  horizontal  line  becomes  indistinct,  and  unless  the  accom- 
modation is  changed,  it  must  be  brought  nearer  the  eye  in  order 
to  be  seen  distinctly.  This  explains  why,  as  a  rule,  horizontal 
lines  can  be  seen  at  a  nearer  distance  than  vertical  ones.  It  fol- 
lows that  in  the  higher  grades  of  meridional  asymmetry  only 
those  lines  whose  directions  correspond  with  one  of  the  principal 
meridians  can  cast  distinct  retinal  images. 

A  certain  degree  of  meridional  asymmetry  exists  in  all  eyes, 
and  cannot  therefore  be  regarded  as  abnormal.  It  can  be  called 
abnormal  only  when  it  exists  to  such  a  degree  that  acuteness  of 


66  ASTIGMATISM. 

vision  suifers  noticeably.  This  is  so  much  the  more  the  case  the 
larger  the  pupil,  the  length  of  the  focal  interval  being  the  same. 
Indistinctness  of  vision  is  the  first  difficulty  of  which  astigmatics 
complain.  In  fact,  under  no  circumstances  do  they  receive  from 
any  object-point  a  distinct  image-point  upon  the  retina,  but  always 
areas  of  diffusion,  which  are  round  when  the  retina  is  at  the  middle 
of  the  focal  interval,  but  which  at  the  ends  of  the  focal  interval 
are  oval  or  nearly  linear,  in  a  direction  corresponding  with  that  of 
the  principal  meridians.  In  general  they  can  see  distinctly  only 
such  lines  as  are  parallel  with  one  of  the  principal  meridians. 

Astigmatics,  on  account  of  their  indistinctness  of  vision,  are 
seldom  capable  of  working  continuously.  Now,  if  hypermetropia 
exist  in  connection  with  astigmatism,  the  symptoms  of  asthenopia 
are  the  more  likely  to  occur,  for  the  astigmatic  is  generally  com- 
pelled to  use  short  distance  for  working,  in  order  to  compensate 
by  the  size  of  the  retinal  images  for  what  they  lack  in  distinct- 
ness. Even  when  only  one  principal  meridian  is  hypermetropic, 
it  is  sufficient  cause  for  the  occurrence  of  accommodative  asthe- 
nopia. If,  for  instance,  the  vertical  principal  meridian  be  emme- 
tropic and  the  horizontal  one  hypermetropic,  then  will  a  distant 
point  appear  upon  the  retina  as  a  horizontal  line, — that  is,  the  ante- 
rior, in  this  case  horizontal  focal  line,  falls  upon  the  retina.  Hori- 
zontal lines  appear  distinct,  vertical  lines  indistinct.  But  in  order 
to  judge  accurately  the  form  of  an  object  it  is  necessary  to  see  its 
vertical  lines  distinctly,  because,  with  reference  to  the  horizontal 
lines,  the  binocular  parallax,  that  is,  the  angle  of  convergence  of 
the  visual  axes,  has  no  determined  size,  and  therefore  is  of  no  helj) 
in  judging  of  distance.  In  order  to  see  distinctly  at  a  distance, 
the  astigmatic,  just  as  the  hypermetrope,  is  compelled  to  make 
an  effort  of  accommodation  corresponding  to  the  hypermetropia  in 
the  horizontal  meridian,  in  order  to  bring  the  posterior  vertical 
focal  line  upon  the  retina,  and  so  to  see  vertical  lines  distinctly. 
An  effort  of  accommodation  is  necessary,  even  when,  in  order  to 
receive  from  every  object-point  as  small  a  circle  of  diffusion  as 
possible,  the  middle  of  the  focal  interval,  and  not  the  posterior  focal 
line,  is  brought  upon  the  retina.  The  same  is  true  for  near  vision  ; 
the  demand  upon  the  accommodation  is  always  greater  than  in 
emmetropia.  On  account  of  the  preponderance  of  vertical  lines 
in  our  letters  it  is  advantageous  when  reading  to  bring  the  poste= 


ASTIGMATLSI^^  67 

rior  focal  line,  when  it  has  a  vertical  direction,  upon  the  retina, 
although  it  involves  a  greater  effort  of  accommodation.  If  hyper- 
metropia  exist  in  both  principal  meridians,  but  in  different  degrees, 
accommodative  asthenopia  is  so  much  the  more  likely  to  occur. 

The  relations  are  more  favorable  when  emmetropia  exists  ip 
the  horizontal  principal  meridian  and  myopia  in  the  vertical  one. 
With  perfect  rest  of  the  accommodation  the  posterior  focal  line 
falls  then  upon  the  retina,  and  vertical  lines  are  therefore  distinctly 
seen,  while  by  narrowing  of  the  palpebral  fissure  the  circles  of 
diffusion  are  made  smaller,  and  horizontal  lines  are  also  seen  more 
distinctly.  Astigmatics  often  avail  themselves  of  this  advantage. 
If  the  directions  of  the  principal  meridians  be  neither  exactly  ver- 
tical nor  horizontal,  astigmatics  often  assume  instinctively  an  in- 
clined position  of  the  head,  by  which  that  principal  meridian  best 
suited  to  the  purposes  of  vision  is  placed  in  the  most  advantageous 
position. 

Astigmatics  do  not  generally  complain  of  other  optical  disturb- 
ances which  are  the  necessary  result  of  meridional  asymmetry, 
such,  for  instance,  as  that  a  square  appears  elongated,  and  a  circle 
elliptical. 

If  congenital  amblyopia  (V  =  f  or  ^  or  -^)  give  reason  to 
suspect  the  existence  of  astigmatism,  the  vision  for  distance  is  first 
to  be  determined,  and  it  is  then  to  be  tried  if  any  improvement 
can  be  made  with  concave  or  convex  glasses ;  for  astigmatism  may 
exist  with  either  myopia  or  hypermetropia.  If  spherical  lenses 
cause  no  improvenient,  or  if  they  cause  slight  improvement,  but 
not  distinct  vision,  it  is  next  to  be  determined 

(1)  If  meridional  asymmetry  exists? 

(2)  What  is  the  direction  of  the  principal  meridians? 

(3)  What  is  the  condition  of  refraction  in  each  of  the  principal 
meridians  ? 

The  first  two  questions  can  generally  be  determined  by  oph- 
thalmoscopic examination.  For  the  functional  examination  it 
is  best  to  use  certain  systems  of  lines.  Javal's*  optometer  Is  a 
contrivance  with  which  to  determine  the  existence  of  astigmatism. 
Instead  of  this  complicated  Instrument  we  may  use  a  system  of 
lines  placed  at  a  definite  distance ;  the  patient  looks  at  these  lines 

*  Annales  d'Oculistique;  1866. 


68 


ASTIGMATISM. 


with  each  eye  separately,  and  it  is  determined  experimentally 
with  what  lens  his  vision  is  most  improved.  Among  these  sys- 
tems of  lines  are  Becker's,  and  the  letters  of  Pray  and  Heymann, 
or,  perhaps  the  very  best,  those  which  accompany  Snellen's  test 
letters,  and  which  are  shown  on  a  reduced  scale  in  Fig,  13,  The 
lines  are  arranged  in  the  form  of  a  half-star,  since  a  figure  of  that 
shape  embraces  lines  running  in  every  conceivable  direction. 
Their  deviation  from  the  perpendicular  is  expressed  in  degrees, 
which  are  marked  with  the  positive  sign  on  the  right  side  of  the 
perpendicular  and  with  the  negative  sign  on  the  left. 

Fig.  13. 


oVcrtLcaL^ 


The  lines  are  placed  at  a  distance  suited  to  the  vision  of  the 
patient,  and  he  is  directed  to  look  at  them  with  one  eye  while  the 
other  is  covered.  If  concave  or  convex  glasses  improve  distant 
vision,  the  examination  is  to  be  conducted  with  their  help.  Care 
should  be  taken  that  the  head  be  held  erect,  and  that  the  eyes  be 
well  opened,  so  that  the  palpebral  fissure  does  not  act  as  a  steno- 
paic  slit.  If,  for  instance,  there  be  emmetropia  in  the  horizontal 
and  myopia  in  the  vertical  meridian,  then  will  a  distant  luminous 
point  throw  its  image  upon  the  retina  in  the  form  of  a  vertical 
line,  since  the  posterior  focal  line,  which  in  this  case  is  vertical, 
falls  with  relaxed  accommodation  exactly  on  the  retina. 

Consequently,  only  the  vertical  lines  in  the  figure  will  be  seen 
distinctly,  the  others  being  less  sharply  defined.  If,  on  the  con- 
trary, there  be  hypermetropia  in  the  horizontal  and  emmetropia  in 


ASTIGMATISM.  69 

the  vertical  meridian,  then  only  the  horizontal  lines  cast  distinct 
retinal  images.  For  the  same  reasons  would  one  or  the  other  of 
the  inclined  lines  appear  distinct  if  the  direction  of  the  principal 
meridians  were  not  exactly  vertical  or  horizontal.  It  is  next  to 
be  experimentally  ascertained  what  concave  or  convex  cylindrical 
lens  corrects  the  meridional  asymmetry  and  causes  all  the  lines  to 
appear  equally  distinct. 

In  order  to  determine  more  exactly  the  condition  of  refraction 
in  each  of  the  principal  meridians,  a  stenopaic  slit  with  a  breadth 
of  1  or  2  millimetres  should  be  held  before  the  eye  in  a  direction 
corresponding  with  that  of  the  line  which  is  seen  most  distinctly; 
the  condition  of  refraction  in  the  principal  meridian  is  then  to  be 
determined  in  the  usual  manner  by  the  aid  of  concave  or  convex 
lenses ;  the  slit  is  then  to  be  placed  at  an  angle  of  90°  with  its 
former  position,  and  the  condition  of  refraction  in  the  second 
principal  meridian  to  be  determined  in  the  same  way.  The  dif- 
ference between  the  condition  of  refraction  in  the  two  principal 
meridians  shows  the  degree  of  the  astigmatism. 

If  one  of  the  principal  meridians  is  emmetropic,  Donders  calls 
the  asymmetry  "simple  astigmatism."  He  distinguishes  a  simple 
myopic  and  a  simple  hypermetropic  form ;  generally,  in  the 
myopic  form  the  emmetropic  principal  meridian  is  horizontal, 
and  in  the  hypermetropic  form  it  is  vertical. 

Compound  astigmatism  is  where  the  same  anomaly  of  refraction 
exists  in  both  principal  meridians,  but  in  a  different  degree;  there 
may  be  myopic  or  hypermetropic  compound  astigmatism. 

INIixed  astigmatism  is  where  myopia  exists  in  one  principal 
meridian  and  hypermetropia  in  the  other. 

Donders*  has  made  numerous  ophthalmometric  measurements 
of  the  curvature  of  the  cornea  in  cases  of  regular  astigmatism. 
He  has  proved  that  a  considerable  meridional  asymmetry  of  these 
curvatures  must  be  regarded  as  the  principal  cause  of  this  anomaly 
of  refraction.  Still,  he  found  that  neither  the  degree  of  astigma- 
tism, as  calculated  from  the  difference  of  curvature  of  the  cornea 
in  the  principal  meridians,  nor  the  direction  of  those  meridians, 
corresponds  absolutely  with  the  actual  condition  of  refraction  of  the 
entire  refracting  apparatus  of  the  eye,  obtained  experimentally. 

*  Arch.  f.  Ophth.,  B.  x.  2,  pag.  83. 


70  ASTIGMATISM. 

The  degree  of  astigmatism  for  the  entire  eye  is  generally  less 
than  can  be  calculated  from  the  asymmetry  of  the  cornea,  and 
consequently  less  than  it  Avould  be  if  only  the  corneal  asymmetry 
were  concerned. 

Carrying  his  calculation  still  further,  Donders  arrived  at  the 
conclusion,  that  up  to  a  certain  degree  the  asymmetry  of  the  cor- 
nea is  compensated  for  by  a  similar  but  opposite  asymmetry  in 
the  lens.  The  maximum  of  curvature  in  the  lens  is  still  more 
constantly  in  the  horizontal  than  that  of  the  cornea  is  in  the  ver- 
tical direction.  Asymmetry  of  the  lens  alone  seems  scarcely  ever 
to  occur.  If,  however,  the  asymmetry  of  the  cornea  exist,  there 
is  almost  certain  to  be  asymmetry  of  the  lens  also.  Generally, 
however,  that  of  the  cornea  is  the  greater,  and  the  resulting 
refractive  effect  approaches,  therefore,  more  nearly  that  of  the 
cornea. 

From  exact  statistics  which  Snellen*  compiled  with  reference 
to  the  principal  meridians,  he  found  the  meridian  of  shortest  focal 
length  to  be  exactly  vertical  in  50.5  per  cent,  and  to  be  horizontal 
in  9  per  cent,  of  all  cases;  in  40.5  per  cent,  of  all  cases  its  direc- 
tion was  found  to  be  about  as  often  in  one  as  in  another  of  the 
other  directions.  The  direction  of  the  principal  meridians  in 
both  eyes  is  generally  symmetric.  There  exists  no  essential  dif- 
ference in  reference  to  the  direction  of  the  meridian  of  shortest 
focal  distance  in  myopic  and  hypermetropic  astigmatism  ;  in  this 
respect  the  degree  of  the  astigmatism  seems  to  exert  no  influence. 

Correction. — All  the  symptoms  of  regular  astigmatism  may 
be  illustrated  by  the  help  of  cylindric*al  lenses,  which  cause  the 
same  asymmetric  refraction  of  light  as  occurs  in  astigmatic  eyes. 
From  this  it  is  evident  that  regular  astigmatism  can  be  corrected 
by  cylindrical  lenses,  which  have  the  same  degree  of  asymmetry, 
but  which  act  in  an  opposite  sense. 

The  degree  of  the  astigmatism  gives,  therefore,  the  number  of 
the  positive  or  negative  cylindrical  lens  necessary  for  its  correction. 

Theoretically,  it  makes  no  difference  whether  we  increase  the 
focal  distance  of  the  vertical  meridian  till  it  equals  that  of  the 
horizontal  meridian,  by  means  of  a  concave  cylindrical  lens,  with 
its  axis  held  in  a  horizontal  direction,  or  whether  we  equalize  the 

*  Arch.  f.  Ophth.,  B.  xv.  2,  pag.  199. 


ASTIGMATISM.  71 

condition  of  refraction  in  the  two  principal  meridians  by  in- 
creasing the  refraction  in  the  horizontal  meridian  by  means  of  a 
convex  lens  with  its  axis  vertical.  In  practice,  however,  each  par- 
ticular case  will  present  grounds  upon  which  to  decide  whether 
concave  or  convex  glasses  should  be  used. 

If  there  be  emmetropia  in  the  vertical  meridian  and  Hyi  ^" 
the  horizontal  meridian,  then  will  a  cylindrical  lens  of  -|-  -^j  cor- 
rect the  error,  if  it  be  held  with  its  axis  vertical  before  the  eye; 
since  rays  of  light  which  diverge  in  the  plane  of  the  axis  of  the 
cylinder  suffer  no  refraction,  while  rays  which  diverge  in  a  plane 
at  right  angles  to  the  axis  experience  a  refraction  proportionate  to 
the  radius  of  curvature.  Or  suppose  that  in  the  vertical  meridian 
M^  be  found,  and  in  the  horizontal  meridian  M2^,  then,  since 
J — Yt  =  T2}  ^^tS"  ^^  present,  and,  according  to  our  classification, 
it  is  compound  myopic  astigmatism.  A  cylindrical  lens  — ^c 
is,  in  this  case,  sufficient  to  correct  the  astigmatism  ;  held  before 
the  eye,  with  its  axis  horizontal,  it  does  not  affect  the  myopia 
existing  in  that  meridian  ;  its  curved  surfaces,  however,  do  reduce 
the  myopia  in  the  vertical  meridian,  but  do  not  neutralize  it, 
since  M^ — i^=2T'  '^^^^  astigmatism  is  then  corrected,  since 
M2^  exists  in  both  principal  meridians. 

For  near  objects,  under  these  circumstances,  a  concave  cylin- 
drical lens  ( —  -j^c)  suffices,  but  for  distinct  distant  vision  it  is 
necessary  to  correct  the  myopia  by  a  spherical  lens.  A  sphero- 
cylindrical lens  — tV*^  ^ — Ti^*  would  neutralize  at  the  same 
time  the  astigmatism  and  the  myopia,  and  such  lenses  should  be 
employed  under  the  same  restrictions  as  correcting  concave  glasses 
in  general.  In  compound  hypermetropic  astigmatism,  on  the 
contrary,  it  is  always  necessary  to  correct  the  hypermetropia 
which  exists  after  the  correction  of  the  astigmatism  ;  this  is  done 
by  convex  sphero-cylindrical  lenses.  When  there  is  not  sufficient 
accommodative  power,  it  may  be  necessary  to  bring  the  far  point 
somewhat  nearer  to  the  eye. 

Mixed  astigmatism  is  also  corrected  by  sphero-cylindrical  lenses. 
If,  for  instance,  there  be  M^  in  the  vertical  and  11^  in  the 


*  As  indicates  astigmatism;  c  =r  cylindrical ;  s^  spherical;  O  indicates 
that  a  spherical  curved  surface  is  combined  with  a  cylindrical  curved  surface 
to  form  a  sphero-cylindrical  lens. 


72  ASTIGMATISM. 

horizontal  meridian,  we  have  As|^;  for  since  the  value  of  the  hy- 
permetropia  must  in  our  calculation  be  affected  with  the  negative 
sign,  we  have  -^-^  —  ( — 2V)  =  iV  +  2T  "=  i-  ^^  ^o'^^'  ^^'*^  place 
before  the  eye  a  cylindrical  convex  lens  of  8  inches  focal  distance 
(|-c),  with  its  axis  placed  vertically,  the  myopia  in  the  vertical 
meridian  remains  unchanged ;  the  hypermetropia  in  the  horizontal 
meridian  is,  on  the  contrary,  so  much  over-corrected  that  M^l^- 
is  the  result  (-|-  —  ^=t2")'  For  distinct  distant  vision,  therefore, 
there  must  be  added  to  the  cylindrical  lens  |-c,  a  spherical  curved 
surface  of  — -p^. 

Instead  of  sphero-cylindrical  lenses,  one  may,  in  all  cases,  choose 
bi-cylindrical  lenses  with  their  axes  crossing  each  other  at  right 
angles,  since  in  that  case  each  of  the  cylindrical  surfaces  corrects 
the  ametropia  of  one  of  the  principal  meridians. 

The  improvement  of  vision  to  be  attained  by  the  use  of  cylin- 
drical glasses  varies  greatly,  according  to  whether  the  defect  of 
vision  depends  upon  regular  astigmatism  alone,  or  whether  com- 
plications exist.  A  very  considerable  degree  of  irregular  astigma- 
tism often  complicates  regular  astigmatism ;  this  appears  to  be 
especially  true  of  those  cases  \i\  which  the  asymmetry  is  princi- 
pally in  the  lens.  Moreover,  it  is  very  probable  that  astigmatism, 
like  hypermetropia,  is  often  complicated  by  congenital  amblyopia. 
These  two  circumstances  explain  the  fact,  that  often  no  improve- 
ment in  vision  is  to  be  obtained  by  the  use  of  cylindrical  lenses  in 
cases  where  the  presence  of  regular  astigmatism  can  be  recognized 
with  certainty  by  ophthalmoscopic  examination.  The  same  causes 
often  make  it  difficult  to  determine  exactly  the  degree  of  the 
astio-matism.  Upon  examination  with  the  stenopaic  slit,  vision  is 
equally  bad  or  good  with  a  series  of  spherical  lenses,  and  it  is  im- 
possible to  say  which  expresses  the  degree  of  refraction  correctly. 
One  attains  about  the  same  result  when  he  seeks  empirically  for 
that  cylindrical  glass  with  which  vision  is  best.  He  will  find, 
just  as  in  the  examination  with  the  stenopaic  slit,  that  cylindrical 
lenses  with  quite  different  focal  lengths  perform  equal  service.  In 
the  case  of  concave  cylindrical  lenses,  we  follow  the  rule  for  the 
choice  of  concave  spherical  lenses,  and  order  the  weakest,  with 
which  equally  good  vision  can  be  attained.  But  with  convex 
cylindrical  glasses  it  is  not  important  to  observe  the  analogy  of 
practice  in  hypermetropia,  and  choose  the  strongest  with  which 


ASTIGMATISM.  73 

distant  vision  is  relatively  best,  since  on  looking  obliquely  through 
the  lenses,  an  act  impossible  to  avoid  in  wearing  spectacles,  the 
cylindrical  lenses  lose  their  centring  and  cause  distortion  of  the 
retinal  images,  which  is  so  much  the  more  disturbing-  the  shorter 
the  focal  length  of  the  lens. 

Cylindrical  lenses  give  great  relief,  even  in  cases  where  they 
produce  no  complete,  but  only  a  partial,  correction  of  vision. 
Frequently,  accommodative  asthenopia,  which  cannot  be  over- 
come by  spherical  convex  glasses,  disappears  after  correction  of 
the  astigmatism,  even  where  normal  distinctness  of  vision  cannot 
be  attained. 

In  a  very  respectable  minority  of  cases  the  correction  of  vision 
attainable  by  cylindrical  lenses  is  entirely  satisfactory. 

Mention  must  be  finally  made  of  the  Stokes  lens,  an  ingenious 
instrument  which  may  be  used  for  the  diagnosis  of  astigmatism. 
It  consists  of  two  piano-cylindrical  lenses  of  equal  focal  distance, 
the  one  concave,  the  other  convex.  If  these  be  placed  with  their 
plane  surfaces  in  apposition  and  their  axes  parallel  to  each  other, 
then  the  cylindrical  surfaces  are  also  parallel,  and  the  instrument 
acts  exactly  like  a  glass  with  plane  surfaces.  If,  however,  one 
glass  be  so  turned  that  its  axis  forms  an  angle  of  90°  with  the 
axis  of  the  other,  there  then  exists  an  asymmetry  whose  value 
equals  the  entire  difference  of  the  two  lenses.  If  for  instance  the 
two  combined  glasses  have,  the  one  a  positive  and  the  dther  a  neg- 
ative focal  distance  of  10  inches,  then,  with  parallel  axes,  they  will 
act  as  a  plane  glass;  with  axes  crossing  each  other  at  right  angles 
the  optical  value  of  the  asymmetry  is  ^=^,  Any  desired  degree 
of  asymmetry  up  to  this  maximum  may  be  produced  by  the  revo- 
lution of  the  lenses,  consequently  every  degree  may  be  corrected 
also. 

In  the  practical  use  of  this  instrument  it  is  to  be  remembered 
that  all  is  not  done  when  the  meridional  asymmetry  is  corrected. 
If  the  condition  of  refraction  in  both  principal  meridians  be  re- 
duced to  one  and  the  same  degree  of  myopia  or  hypermetropia,  we 
must,  in  order  to  make  this  step  of  any  practical  value,  still  fur- 
ther determine  the  degree  of  the  remaining  myopia  or  hyperme- 
tropia. 

An  exact  manipulation  of  this  ingenious  instrument  has  there- 
fore its  special  difficulties,  and  since  cylindrical   glasses  are  so 

6 


74  ANISOMETROPIA. 

easily  obtained,  their  use  is  generally  preferable  to  that  of  Stokes's 
lens. 

DIFFEKEISrCE    OF    KEFKACTION   IN   THE    TWO   EYES   (ANISO- 
METROPIA). 

As  a  rule,  both  eyes  have  the  same  condition  and  degree  of  re- 
fraction, although  slight  differences  of  perhaps  -^,  or  even  less, 
are  quite  frequent.  The  remarks  which  follow,  have  reference 
principally  to  cases  in  Avhich  the  difference  in  refraction  is  con- 
siderable. 

There  occur  all  possible  combinations  in  the  refractive  condition 
of  the  two  eyes.  For  instance,  with  emmetropia  in  one  eye,  the 
other  may  be  myopic  or  hypermetropic ;  or  there  may  be  the  same 
anomaly  of  refraction  in  both  eyes,  but  in  a  different  degree ;  in 
high  degrees  of  acquired  myopia  such  differences  are  relatively 
frequent. 

Cases  occur  of  hypermetropia  in  one  eye  and  myopia  in  the 
other.  So,  too,  unilateral  astigmatism  may  occur;  but  in  such 
cases  the  rule  of  correspondence  in  the  condition  of  refraction 
holds  good  thus  far,  that  with  myopic  astigmatism  in  one  eye 
there  is  myopia  in  the  other,  or  with  hypermetropic  astigmatism 
in  one  eye  there  is  hypermetropia  in  the  other. 

Loss  of  the  lens  on  one  side,  for  instance,  by  catara(?t  operation, 
is  to  be  mentioned  in  this  connection  ;  and  finally  the  paresis  of 
accommodation  on  one  side  has  the  same  physiological  effect  on  near 
vision  that  differences  of  refraction  have  upon  vision  in  general. 

Under  these  circumstances,  only  one  eye  can  receive  a  distinct 
retinal  image,  while  the  image  in  the  other  eye  is  made  up  of 
circles  of  diffusion;  this  is  true  for  every  distance  at  which  each 
eye  alone  can  receive  a  distinct  image. 

This  is  a  consequence  of  the  fact  that  the  accommodative  appa- 
ratus of  both  eyes  is  simultaneously  and  equally  innervated.  If 
one  eye  is  emmetropic  with  its  near  point  at  4  inches  (i=:i),  while 
the  other  possesses  the  same  power  of  accommodation  with  myopia 
-^  and  a  near  point  at  3  inches,  then  each  eye  alone  may  see  dis- 
tinctly a  point  6  inches  distant,  but  not  at  the  same  time.  If  the 
myopic  eye  accommodate  to  a  distance  of  6  inches,  it  employs  an 
effort  of  accommodation  equal  to  ^,  which,  however,  affects  equally 
the  other  eye,  and  adjusts  it  upon  a  distance  of  12  inches. 


ANISOMETEOPIA.  75 

Under  these  circumstances  it  can  be  shown,  by  the  help  of 
prisms,  that  for  such  distances  as  lie  within  the  range  of  accom- 
modation it  is  always  only  one  eye  which  is  properly  adjusted 
and  receives  distinct  retinal  images.  The  patient  is  to  look  at 
some  suitable  object,  say  a  fine  line,  Avhile  a  weak  prism  of  per- 
haps 4°  or  5°  is  held  with  its  base  either  up  or  down  in  front  of 
the  other  eye;  double  images  will  then  be  seen,  of  which  only 
one,  and  that  corresponding  to  the  properly-adjusted  eye,  will 
appear  distinct.  In  all  the  cases  of  difference  of  refraction  with 
good  vision  on  both  sides,  which  I  have  examined  in  this  manner, 
it  could  be  shown  that  only  that  eye  was  used  for  near  vision 
which  receivecj  distinct  retinal  images  with  the  least  effort  of 
accommodation ;  for  instance,  in  unilateral  myopia,  always  the 
myopic  eye.  Where  there  is  difference  in  refraction,  under  all 
circumstances  it  is  only  one  eye  which  receives  a  distinct  retinal 
image.* 

A  normal  binocular  vision  may  exist  in  spite  of  the  dissimi- 
larity of  the  opposite  retinal  images,  as  can  be  proved  by  Hering's 
experiment  (see  p.  113),  and  the  circles  of  diffusion  in  the  one 
eye  are 'overlooked  in  the  binocular  image. 

When  in  one  eye  there  is  emmetropia  and  in  the  other  myopia 
of  a  moderate  degree  (at  least  ^),  but  with  good  vision  on  both 
sides,  there  is  but  slight  demand  made  on  the  accommodation,  for 
the  myopic  eye  is  used  for  near  and  the  emmetropic  for  distant 
vision.  In  high  degrees  of  unilateral  myopia  there  often  develops 
a  characteristic  form  of  strabismus  divergens  alternans. 

If  one  eye  be  hypermetropic  and  the  other  emmetropic  or 
myopic,  the  effort  of  accommodation  adjusts  only  the  latter  eye. 
Generally,  under  these  circumstances,  the  hypermetropic  eye  is 
amblyopic,  but  the  degree  of  amblyopia  is  usually  much  over- 
estimated by  patients  accustomed  to  very  slight  efforts  of  accom- 
modation. 

If  on  both  sides  there  be  hypermetropia,  but  in  different  degrees, 
it  may  favor  the  occurrence  of  strabismus  convergens,  in  which, 
supposing  there  is  equal  distinctness  of  vision,  the  less  hyperme- 
tropic eye  is  used  for  fixation.     On  the  other  hand,  with  bilateral 


*  iSchneller's  contrary  assertion  (Arch.  f.  Ophth.,  Bd.  xvi.  pag.  176)  does 
not  a<i;ree  with  mv  observation. 


76  ANISOMETROPIA. 

myopia  of  high  grade  and  different  degrees,  relative  strabismus 
divergens  easily  develops  with  an  inclination  to  employ  the  sharpest- 
sighted  and,  as  a  rule,  least  myopic  eye. 

If  we  have  difference  of  refraction  in  the  two  eyes,  the  question 
often  arises  whether  this  difference  is  to  be  equalized  by  different 
lenses. 

If  there  exist  under  these  circumstances  the  mutual  visual  act 
and  binocular  fixation,  it  is  first  to  be  determined  which  eye  pos- 
sesses the  better  vision  and  at  the  same  time  the  less  anomaly  of 
refraction.  There  follows,  then,  for  this  eye  the  choice  of  the 
necessary  lens  according  to  the  usual  rules.  Generally  it  is  advan- 
tageous to  prescribe  the  same  lens  for  the  other  eye^  The  patients 
are  accustomed  to  the  dissimilarity  of  their  retinal  images,  and 
the  equalization  of  their  refraction  they  find  only  an  inconvenience, 
and  that  so  much  the  more,  since  absolute  similarity  of  the  two 
images  as  respects  their  size  cannot  be  attained.  If  allowed  to 
choose  for  themselves  between  spectacles  with  glasses  alike  on  both 
sides  and  those  with  unlike  glasses,  such  patients  generally  prefer 
the  first. 

There  occur,  however,  exceptions  to  this  rule.  For  instance, 
often  in  myopia,  with  slight  difference  of  refraction  (perhaps  3^  or 
-^),  an  equalization  of  refraction  gives  better  vision ;  sometimes, 
when  the  difference  is  greater,  a  partial  equalization  gives  the  same 
result.  So  too,  in  hypermetropia  with  deficient  vision,  the  rela- 
tively best  binocular  vision  is  sometimes  attained  by  providing 
each  eye  with  its  best  correcting  lens. 

If,  as  is  seldom  the  case,  the  eye  with  the  best  vision  has  at  the 
same  time  the  greatest  degree  of  anomalous  refraction,  it  is  ad- 
vantageous to  give  the  other  eye  a  proportionately  weak  lens. 

If,  as  for  instance  with  myopia  on  one  side  and  emmetropia  on 
the  other,  the  eyes  are  used  interchangeably,  there  is  generally  no 
occasion  for  spectacles. 

PAKALYSIS   OF   ACCOMMODATION. 

Paralysis  of  accommodation  causes  the  same  optical  disturbances 
as  presbyopia.  In  this  respect  it  is  all  the  same  whether  the  near 
point  withdraws  on  account  of  a  loss  of  elasticity  in  the  lens  or 
because  the  muscle  refuses  to  perform  its  office.  There  is,  how- 
ever, this  essential  distinction,  that  in  presbyopia  the  pupil  is  con- 


PARALYSIS    OF   ACCOMMODATION.  77 

tracted,  while,  as  a  rule,  the  sphincter  iridis  participates  in  the 
paralysis,  and  the  pupil  is  dilated  and  immovable.  Often  the 
form  of  the  pupil  is  more  aifected  than  its  size. 

There  occur  also  cases  of  paralysis  of  accommodation  without 
participation  of  the  sphincter  iridis ;  this  is  generally  so  in  paresis 
of  accommodation  following  diphtheritis  faucium.  A  distinction 
closely  allied  to  this  last  is,  that  presbyopia,  the  diminution  of 
accommodation  dependent  on  age,  always  occurs  in  both  eyes 
simultaneously  and  to  an  equal  degree,  while  paralysis  of  accom- 
modation may  be  either  unilateral  or  bilateral. 

In  presbyopia  the  difficulties  of  paralysis  of  accommodation 
are  but  little  noticed ;  so  too  in  myopia,  when  the  far  point  is 
not  more  than  12  or  15  inches  distant,  since  this  distance  is 
generally  sufficient  for  reading,  writing,  etc. 

Emmetropes  are  annoyed  by  indistinctness  of  vision  for  near 
objects ;  they,  however,  see  distinctly  at  a  distance.  With  the  loss 
of  accommodation  hypermetropes  lose  also  the  possibility  of  see- 
ing distinctly  at  a  distance.  The  disturbance  in  vision  gives  the 
impression  of  serious  amblyopia,  and  is  occasionally  confounded 
with  it.  Such  an  error  in  diagnosis  may  be  easily  avoided,  and 
vision  made  distinct  by  such  convex  lenses  as  correct  the  hyper- 
metropia  and  paralysis  of  accommodation. 

All  the  annoyances  of  paralysis  of  accommodation  are  so  much 
the  greater  the  wider  and  more  immovable  the  pupil,  because 
the  size  of  the  circles  of  diffiision  and  the  dazzling  of  light  are 
proportionately  increased. 

Micropia  is  a  characteristic  phenomenon  often  observed  in  con- 
nection with  paralysis  of  accommodation.  Objects  which  with 
full  tension  of  accommodation  may  be  still  seen  plainly,  appear 
diminished,  because  our  judgment  respecting  the  size  of  objects 
depends  not  ou\f  upon  the  size  of  the  retinal  images,  but  also 
upon  the  distance  at  which  we  project  that  image.  Our  judgment 
concerning  the  distance  of  objects  depends  mostly  upon  the  con- 
vergence of  tile  visual  axes  and  the  tension  of  accommodation. 

One  can  very  easily  satisfy  himself  respecting  the  influence  of 
the  convergence  of  the  visual  axes  by  holding  before  his  eyes 
prisms  of  4°' to  6°,  with  the  refracting  angle  turned  outward;  in 
this  way  the  lines  of  vision  relatively  to  the  point  fixed  are  made 
to  diverge  (comp.  Fig.  4,  page  17).     Objects  at  a  distance  of  per- 


78  MICROPIA. 

haps  25  or  30  centimetres  seen  under  an  unusually  small  angle 
of  convergence  appear  enlarged.  The  size  of  the  retinal  images 
remains,  of  course,  unchanged,  but  they  are  referred  to  more  dis- 
tant and  therefore  larger  objects.  In  looking  at  solid  objects  the 
apparent  increase  of  their  third  dimension  is  very  striking. 

For  similar  reasons,  in  paresis  of  accommodation,  with  a  strong 
effort  at  accommodation  an  object  fixed  appears  nearly  as  small 
as  under  normal  conditions  an  object  would  appear  if  placed  at  the 
near  point  and  casting  an  equally  large  retinal  image. 

This  kind  of  myopia  was  first  observed  and  explained  by  Bon- 
ders in  cases  of  paralysis  of  accommodation  by  atropine.  In  gen- 
eral, atropine  mydriasis  affords  a  very  good  opportunity  for  the 
study  of  paralysis  of  accommodation.* 

The  ciliary  muscle  is  innervated  by  the  nervus  oculo-motorius. 
The  course  of  this  nerve  is  therefore  to  be  examined  for  the  cause 
of  the  paralysis  of  accommodation.  Clinically,  we  should  class 
together  in  one  group  those  cases  in  which  not  only  the  accom- 
modation, but  also  all  the  other  muscles  supplied  by  the  oculo- 
motorius  are  either  wholly  or  partially  paralyzed, — that  is,  cases  in 
which  paralysis  of  accommodation  is  only  one  of  the  symptoms  of 
a  paralysis  of  the  oculo-motorius.     Even  when  only  a  few  of  the 

*  Another  form  of  micropia  will  be  described  later  as  a  consequence  of 
retinitis. 

Micropia  has,  in  many  cases,  onl}'  physical  causes.  I  treated  a  physician 
(himself  a  good  observer)  for  rheumatic  paralysis  of  the  abducens  on  the  right 
side,  with  strabismus  convergens  paralyticus  in  the  entire  field  of  vision.  He 
found  that  under  certain  fixed  conditions  the  double  image  seen  excentrically 
appeared  much  smaller  than  the  fixed  object.  The  double  images  of  an  object 
placed  in  the  median  line  appeared,  as  usual,  of  similar  size.  There  occurred, 
however,  a  very  marked  difference  in  the  size  of  the  images  when  the  patient 
placed  himself  opposite  the  wall  of  his  room  and  then  fixed  with  his  left  eye 
an  object  lying  to  his  left.  Evidently  the  explanation  of  this  micropia  can 
be  deduced  neither  from  the  character  of  the  retina  nor  from  the  behavior  of 
accommodation  or  the  muscles  of  the  eye.  Von  Graefe,  who  was  also  inter- 
ested in  the  case,  gave  the  following  explanation  of  the  phenomenon.  The 
retinal  image  in  the  deviating  eye  was  projected  in  a  plane  whose  situation 
was  given  by  the  wall  standing  opposite  to  the  patient.  Now,  since  the  phe- 
nomenon was  observed  always  in  reference  to  objects  at  one  side,  and  since 
the  double  images  were  always  homonymous,  they  were  projected  at  a  place 
on  the  wall  the  distance  to  which  was  less  than  to  the  object  fixed.  Conse- 
quently, the  retinal  image  was  referred  to  an  object  which  at  this  shorter 
distance  would  have  given  a  retinal  image  of  the  same  size. 


PARALYSIS    OF   ACCOMMODATION.  79 

muscles  innervated  by  the  oculo-motorius  are  paralyzed,  the  ac- 
commodation is  seldom  unafFected.  On  the  other  hand,  in  abso- 
lute paralysis  of  accommodation,  and  of  all  the  muscles  supplied 
by  the  oculo-motorius,  the  pupil  shows  only  moderate  dilatation, 
so  that  it  can  be  considerably  more  dilated  by  atropine. 

The  etiology  and  therapeutics  of  these  cases  coincide  exactly 
with  those  of  paralysis  of  the  oculo-motorius. 

Paresis  of  accommodation  in  connection  with  paralysis  of  the 
nervus  abducens  occurs  very  rarely.  This  peculiar  combination 
may  be  explained,  as  Adamiuk*  has  suggested,  by  assuming  that 
exceptionally  fibres  supplying  the  sphincter  of  the  iris  may  ac- 
company the  abducens.  In  the  orbit  these  fibres  always  pass 
through  the  ciliary  ganglion. 

Cases  occur  of  complete  and  incomplete  paralysis  of  accommo- 
dation, as  an  idiopathic  affection  without  participation  of  the  other 
branches  of  the  oculo-motorius. 

In  the  incomplete  form  the  near  point  recedes  from  the  eye, 
but  there  is  still  some  power  of  accommodation,  and  the  pupil  is 
often  unsymmetrically  dilated ;  in  the  complete  form  accommoda- 
tion is  lost,  and  then  often  the  pupil  is  dilated  ad  maximum, 
exactly  as  in  atropine  mydriasis. 

The  etiology  of  these  cases  is  generally  obscure.  A  cold  is 
often  regarded  as  a  cause,  and  often  no  cause  can  be  found.  Many 
cases  are  due  to  brain-disease. 

The  prognosis  in  reference  to  the  duration  and  curability  of  the 
disease  is  always  uncertain.  In  reference  to  retaining  the  power 
of  vision,  it  is  generally  favorable:  still,  it  must  be  remembered 
that  the  paralysis  of  accommodation  may  be  the  precursor  of 
deeper-seated  disturbances  in  the  central  nervous  system. 

Treatment. — At  first  an  an ti- rheumatic  treatment  generally 
seems  best, — bleeding  from  the  temple,  cathartics,  diaphoretics, 
inunction  of  stimulating  substances  on  the  forehead  (for  instance, 
veratrin  salve),  vesication  behind  the  ears  and  upon  the  neck,  and 
finally  electricity.  For  internal  use  ergot  is  recommended.  At 
the  same  time  the  use  of  the  eyes  must  be  limited  as  much  as 
possible. 

A  very  happy  but  transitory  effect  is  produced  by  the  extract 

*  Centralblatt  f.  die  med.  Wissenschaften,  1870,  N.  12. 


80  PARALYSIS    OF    ACCOMMODATION. 

of  Calabar  bean.  It  contracts  the  pupil,  and  where  there  is  only 
partial  paralysis  of  accommodation  it  causes  the  range  of  accom- 
modation to  approach  the  eye.  Indeed,  one  can  observe  a  tem- 
porary positive  increase  in  the  range  of  accommodation,  which 
Donders*  and  Hamer  have  shown  to  be  the  physiological  effect  of 
the  Calabar  bean.  All  the  inconveniences  of  paralysis  of  accom- 
modation may  in  this  way  be  relieved  for  some  hours.  The  hopes 
placed  on  extract  of  Calabar  bean  as  a  remedy  by  which  to  effect 
a  radical  cure  have,  however,  not  been  realized. 

Many  cases  of  paresis  of  accommodation  recover  after  some 
weeks  or  months,  either  with  or  without  this  treatment.  A  greater 
number,  however,  are  not  benefited  by  it.  In  such  cases  the  prin- 
cipal thing  to  be  done  is  to  relieve  the  optical  disturbances. 
When  the  affection  is  on  one  side  only,  these  disturbances,  on 
account  of  the  dissimilarity  of  the  retinal  images,  are  at  first  very 
unpleasant,  especially  when  reading  or  writing,  provided  the  eye 
is  not  myopic.  The  retinal  images  of  the  affected  eye  are  not 
only  diffuse,  but,  on  account  of  the  dilatation  of  the 'pupil,  they 
are  at  the  same  time  more  brightly  illuminated  than  those  of  the 
other  eye,  and  therefore  cannot  be  so  easily  neglected.  A  cor- 
rection by  means  of  a  convex  lens,  which  adjusts  the  eye  for  the 
distance  necessary  for  work,  is  therefore,  at  first,  generally  very 
agreeable;  later,  the  patients  become  accustomed  to  the  dissimi- 
larity of  the  retinal  images,  just  as  in  difference  of  refraction, 
and  they  then  generally  lay  the  spectacles  aside. 

The  disturbances  in  bilateral  paralysis  of  accommodation  are 
much  more  important,  especially  when  it  is  complete  and  is  asso- 
ciated with  excessive  dilatation  of  the  pupil.  It  is  true  that  the 
defect  in  accommodation  may  be  compensated  for  by  a  convex 
lens,  but  only  for  one  particular  distance.  An  emmetrope,  for 
instance,  with  complete  bilateral  paralysis  of  accommodation,  will, 
with  convex  12,  see  distinctly  at  a  distance  of  12  inches,  but  at 
that  distance  only.  Whether  the  object  be  moved  toward  or 
from  him,  there  begin  to  be  circles  of  diffusion,  which  are  so  much 
the  greater  the  wider  the  pupil.  For  these  cases  the  extract  of 
Calabar  bean  gives  us  the  means  of  contracting  the  pupil,  and 
so  making  the  use  of  convex  glasses  for  near  vision  easier  and 

*  L.  c,  pag.  518. 


PARALYSIS    OF    ACCOMMODATION.  81 

pleasanter,  except  where  the  mydriasis  is  due  to  cerebral  causes, 
and  there  the  Cahibar  refuses  to  do  its  work.  The  sokitiou  should 
be  of  such  a  strength  that  one  drop  in  the  conjunctival  sac  is  suf- 
ficient to  hold  the  pupil  contracted  for  about  twelve  hours.  Its 
use  may  be  continued  a  long  time. 

Paralysis  of  accommodation  after  diphtheritis  faucium  occurs 
as  one  of  the  symptoms  of  a  very  peculiar  group  of  paralyses 
which  appear  as  sequelae  to  diphtheritis,  and  generally  from  three 
to  six  weeks  after  it.  The  severity  of  the  diphtheritic  disease  has 
no  influence  upon  them ;  paralyses  may  occur  after  even  the  mildest 
cases.  A  paralysis  of  the  muscles  of  deglutition  is  always  the 
first  to  appear;  its  symptoms  are  difficulty  in  swallowing,  a  nasal 
tone,  and  a  disagreeable  secondary  tone  accompanying  certain 
consonants.  According  to  Pagenstecher,*  this  throat  paralysis  is 
generally  unilateral ;  there  is  on  the  one  side  relaxation  of  the 
velum  and  pharynx,  an  oblique  position  of  the  uvula  and  epi- 
glottis, imperfect  closure  of  the  glottis  and  anaesthesia  of  the  parts 
affected.  After  this  follows  paralysis  of  the  accommodation,  and 
often  of  some  of  the  muscles  of  the  eye.  Later,  there  may  be 
paralytic  symptoms  in  the  extr-emities;  and  lastly,  and  this  is 
most  alarming,  paralysis  of  the  muscles  of  respiration,  which  may 
end  in  death. 

As  a  rule,  the  accommodation  is  not  absolutely  paralyzed.  The 
pupils  generally  are  only  slightly  dilated,  and  perhaps  there  is  no 
dilatation  to  be  recognized,  and  only  a  slight  diminution  in  their 
motility. 

Jacobsonf  found  in  certain  cases  where  he  used  atropine  energet- 
ically during  the  paresis  of  accommodation,  a  much  higher  degree 
of  hypermetropia  than  could  be  demonstrated  by  the  atropine 
mydriasis  after  recovery  from  the  paralysis.  He  drew  from  this 
the  conclusion  that  not  only  the  power  of  accommodation  but  also 
the  refraction  is  decreased  as  a  consequence  of  diphtheritis.  Never- 
theless, these  cases  may  indicate  that  during  the  paresis  of  accom- 
modation the  latent  tension  is  relaxed  either  absolutely  or  to  a 
degree  easily  overcome  by  atropine,  while  with  normal  accommoda- 


*  Pagenstecher  (aus  Elberfeld)  klin.  Monatsbl.  f.  Augenheilk.,  1864,  pag. 
358. 
t  Arch.  f.  Ophth.,  B.  x.  2,  pag.  47. 


82  PARALYSIS   OF   ACCOMMODATION. 

tion  considerable  latent  tension  persists.  It  is  then  several  days 
before  the  eye  can  be  rednced  to  its  true  refractive  condition  by 
atropine.  Probably  the  uninterrupted  tension  of  accommodation 
induces  in  the  eyes  of  most  youthful  hypermetropes  a  modification 
in  the  form  of  the  lens,  which  does  not  yield  immediately,  but 
only  very  gradually,  to  atropine  mydriasis. 

The  prognosis  in  diphtheritic  paralysis  is  generally  favorable  : 
it  is  grave  only  in  the  rare  cases  where  the  muscles  of  respiration 
are  affected. 

The  paralysis  of  accommodation  generally  recovers  spontane- 
ously in  from  six  to  eight  weeks ;  still,  the  recovery  may  be 
hastened  by  daily  dropping  the  Calabar-bean  extract  in  the  eye, 
or  by  the  use  of  electricity,  while  the  disturbances  of  vision 
may  be  relieved  by  spectacles  which  bring  the  near  point  up  to 
about  12  inches.  A  moderate  use  of  the  muscle  of  accommo- 
dation is  thus  called  into  play,  which  also  may  contribute  to  the 
recovery. 

The  general  health  of  the  patient  usually  requires  at  the  same 
time  tonic  treatment:  iron,  quinine,  good  nourishment,  etc. 

Finally,  there  is  still  a  peculiar  and  quite  frequent  form  of 
mydriasis,  with  paralysis  of  accommodation,  namely,  the  traumatic. 
After  contusions  of  the  eye,  without  any  apparent  wound,  there 
often  appears  an  unsymmetrical  or  a  complete  dilatation  of  the 
pupil,  with  limitation  or  loss  of  accommodation. 

The  prognosis  depends  in  the  first  place  upon  the  nature  of  the 
traumatic  cause.  Even  when,  immediately  after  the  injury,  no 
great  disturbances  of  vision  occur,  there  may  appear  later  not  only 
mydriasis,  but  marked  functional  anomalies,  especially  when  the 
injury  has  caused  luxation  of  the  lens. 

Slight  cases  of  traumatic  mydriasis  often  pass  away  spon- 
taneously. 

The  treatment  depends  upon  the  nature  of  the  injury,  and  at  first, 
at  least,  must  be  antiphlogistic.  Without  there  being  any  paralysis 
of  accommodation,  mydriasis  may  occur  in  consequence  of  irrita- 
tion of  the  cervical  sympathetic.  In  his  own  person,  during  an 
attack  of  hemicrania,  Du  Bois  Reymond*  observed  a  dilatation  of 
the  pupil  on  the  affected  side.     This,  and  the  other  symptoms,  he 

*  Archiv  f.  Anat.  unci  Physiologie,  1860,  pag.  461. 


SPASM   OF    ACCOMMODATION.  83 

regarded  as  a  tetanization  of  the  contractile  tissues  supplied  by 
the  cervical  sympathetic  (mydriasis  spastica*). 

SPASM    OF  ACCOMMODATION. 

In  describing  hypermetropia,  we  mentioned  that  in  most  cases, 
in  young  individuals,  a  part  of  the  hypermetropia  is  masked  by  a 
permanent  tension  of  the  ciliary  muscle,  not  under  the  control  of 
the  will.  In  the  course  of  years  the  latent  hypermetropia  becomes 
manifest  either  by  the  limitation  of  accommodation  (presbyopia)  or 
by  its  paralysis,  either  pathological  or  toxic ;  for  instance,  by  atro- 
pine mydriasis.  The  paralysis  of  accommodation  and  the  atro- 
pine mydriasis  set  aside  not  only  the  voluntary  but  also  the  latent 
tension  of  accommodation,  either  wholly  or  for  the  greater  part. 
When  the  paralysis  passes  away  the  latent  hypermetropia  returns. 
The  condition  is  one  of  persistent  contraction  of  the  muscle,  which 
makes  its  relaxation  beyond  a  certain  limit  impossible ;  uj)  to  that 
limit,  however,  its  action  is  not  interfered  with.  This  condition 
may  be  called  a  tonic  spasm,  but  it  must  not  be  forgotten  that  it 
bears  a  physiological  impress,  since  it  was  introduced,  is  main- 
tained, and  has  become  habitual  in  the  service  of  the  visual  act, 
and  to  neutralize  as  much  as  possible  the  disadvantage  of  hyper- 
metropia. 

The  case  is  somewhat  different  when  anatomical  emmetropia 
or  hypermetropia  is  changed  by  a  tonic  contraction  of  the  ciliary 
muscle  into  apparent  myopia.  The  frequency  of  latent  hyperme- 
tropia makes  it  probable  that,  in  consequence  of  severe  and  con- 
tinuous straining  of  the  accommodation,  especially  in  the  evening 
by  insufficient  light,  youthful  individuals  frequently  lose  the  power 
to  relax  voluntarily  their  accommodation,  and  so  acquire  an  ap- 
parent myopia.  It  is  more  difficult  to  understand  how,  in  myopia 
also,  there  should  arise  a  tonic  tension  of  accommodation  to  cause 
an  apparent  increase  of  the  refraction,  especially  when  there  exist 
those  symptoms  of  irritation  described  on  page  44. 

In  these  cases  of  spasm  of  accommodation  or  apparent  myopia 
the  subjective  symptoms  are  very  similar  to  those  of  accommo- 
dative asthenopia.  The  patients  complain  of  quick  fatigue  and 
pain   while   working,  symptoms    probably  depending   upon   the 

*  Comp.  Hirschler,  Wiener  med.  Woohenschrift,  1873,  No.  17. 


84  SPASxM    OF   ACCOMMODATION. 

fact  that  the  permanent  tension  of  the  muscle  interferes  with  its 
normal  movements  and  endurance.  In  fact,  there  is  often  not 
only  an  approach  of  the  far  point,  but  also  a  withdrawal  of  the 
near  point. 

One  circumstance  is  useful  in  making  the  diagnosis,  and  we 
have  already  referred  to  it  in  connection  with  latent  hyperme- 
tropia :  it  is  the  fluctuation  of  the  tension  of  accommodation  about 
the  limit  of  the  far  point.  Just  as  in  latent  hypermetropia  the 
patients  sometimes  prefer  stronger,  sometimes  weaker,  convex 
glasses,  so  is  the  same  thing  noticed  with  reference  to  concave 
glasses  in  apparent  myopia.  A  certain  diagnosis  can  be  made  only 
by  determining  the  optical  adjustment  of  the  eye  before  and  after 
the  action  of  atropine. 

In  the  treatment  of  apparent  myopia  the  general  care  of  the 
eye  is  of  the  greatest  importance.  In  obstinate  cases  atropine  can 
be  used  continuously  for  two  weeks  ;  blood  may  be  taken  from  the 
temple  by  means  of  the  artificial  leech.  If  hypermetropia  exist, 
it  is  to  be  corrected. 

As  above  intimated,  this  condition  passes  over  without  sharply- 
defined  limits  into  normal  relations.  Even  in  eyes  which,  upon 
examination,  appear  emmetropic,  act  normally  and  give  occa- 
sion for  no  complaints,  there  is  frequently  during  the  atropine 
mydriasis  a  condition  of  refraction  -^  to  -^  weaker.  It  would 
be  hardly  proper  to  class  such  cases  among  those  of  spasm  of 
accom  m  odation . 

It  is,  moreover,  to  be  observed  that  there  are  certain  sources  of 
error  scarcely  to  be  avoided  in  the  methods  of  examination  em- 
ployed in  practice  for  determining  the  acuteness  of  vision  and 
the  condition  of  refraction.  This  must  make  us  careful  to  avoid 
drawing  conclusions  based  upon  slight  differences  observed  in 
examinations  made  at  different  times. 

Of  another  nature  are  certain  hitherto  little-noticed  cases,  in 
which  the  accommodation  is  narrowed  down  to  a  space  very  near 
the  eye. 

The  Calabar  myosis*  presents  a  typical  picture  of  toxic  spasm 
of  accommodation,  such  as  often  develops  pathologically.  A  few 
minutes  after  dropping  into  the  eye  a  10  per  cent,  solution  in 

*  Bonders,  1.  c,  p.  513  ;  v.  Graefe,  Arch.  f.  Ophth.,  Bd.  ix.  3,  pag.  87. 


SPASM   OF   ACCOMMODATION.  85 

glycerin  of  the  extract  of  Calabar  bean  there  begins  a  consider- 
able contraction  of  the  pupil,  which  in  from  twenty  to  thirty  min- 
utes attains  its  maximum.  At  the  same  time  both  the  far  point  and 
the  near  point  approach  the  eye,  and  the  relative  range  of  accom- 
modation is  so  changed  that  too  strong  a  tension  of  accommodation 
is  associated  with  the  convergence  of  the  visual  axes. 

In  about  three-quarters  of  an  hour  after  the  instillation  of  the 
Calabar  extract  the  far  point  begins  gradually  to  recede  again,  and 
after  about  two  hours  attains  its  original  position.  The  simul- 
taneous withdrawal  of  the  near  point  follows  more  slowly,  so  that 
for  some  hours  there  is  an  actual  increase  in  the  range  of  accom- 
modation. The  contraction  of  the  pupil  begins  to  give  way  some 
hours  after  the  instillation,  but  remains  recognizable  for  two  or 
three  days. 

The  subjective  symptoms  are, — 

1.  Pains  which  accompany  every  strong  voluntary  tension  of  the 
ciliary  muscle  when  the  application  has  been  too  strong,  or  when 
there  is  peculiar  sensitiveness  of  the  patient. 

2.  The  entire  field  of  vision  seems  strangely  shaded ;  this  is 
due  to  the  diminished  illumination  caused  by  the  myosis.  After  a 
time  this  symptom  disappears  as  the  retina  accommodates  itself  to 
the  fainter  light. 

3.  There  is  macropia,  the  explanation  of  which  is  analogous  to 
that  of  micropia  in  atropine  mydriasis. 

In  connection  with  spasm  of  the  ciliary  muscle,  mention  must 
be  made  of  those  rare  cases  in  which  even  slight  demands  upon 
the  ciliary  muscle  cause  immediately  severe  pain.  This  condition, 
according  to  Donders,*  occurs  only  in  hypermetropia,  but  it  may 
be  in  cases  of  the  very  lowest  degree.  The  symptoms  are  similar 
to  those  of  accommodative  asthenopia,  but  can  be  distinguished 
from  them  by  the  fact  that  convex  glasses  have  no  influence  upon 
them,  since  the  convergence  necessary  for  near  vision  is  of  itself 
sufficient  to  account  for  the  painful  contraction  of  the  muscle  of 
accommodation.  That  it  is,  however,  an  aifection  of  the  muscle  is 
proved  by  the  fact  that  with  complete  atropine  mydriasis  and  the 
help  of  correcting  convex  glasses  work  can  be  continued  without 
inconvenience. 

*  L.  c,  pag.  241. 


86  MYOSIS. 

Complete  recovery  may  be  obtained  by  continuing  for  months 
the  use  of  atropine. 

There  is  an  entirely  different  cause  for  certain  nervous  diffi- 
culties, which  must  here  be  mentioned,  because  they  give  rise  to 
symptoms  very  similar  to  spasm  of  the  ciliary  muscle.  After 
working  a  short  time,  disturbances  are  felt  in  the  eyes,  which  make 
it  necessary  to  lay  the  work  aside;  often  it  is  not  possible  to 
observe  attentively  either  a  near  or  a  far  object;  generally  other 
nervous  symptoms,  and  often  hysteria,  are  present. 

The  term  myosis  expresses  in  general  every  continuous  contrac- 
tion of  the  pupil;  usually,  however,  those  cases  are  excluded 
which  depend  upon  contraction  of  the  sphincter  pupillse,  caused 
by  irritation  of  the  ocular  branches  of  the  nervus  trigeminus,  as 
by  irritating  substances,  foreign  bodies,  inflammation,  etc. 

Myosis  is  often  only  a  symptom  of  disease  of  the  nervous 
centres,  especially  of  the  spinal  cord;  or  it  may  depend  upon 
peripheral  paralysis  of  the  cervical  filaments  of  the  sympathetic. 

In  many  cases  there  is  no  evident  cause;  especially  in  aged 
persons  one  often  finds  very  small  and  slightly  active  pupils,, 
which  widen  only  a  little  under  the  use  of  atropine. 

MONOCULAR   POLYOPIA   AND   DIPLOPIA. 

There  is,  finally,  one  symptom  to  be  mentioned  which  may  occur 
in  all  the  anomalies  of  refraction  and  accommodation,  and  is  then 
always  to  be  explained  upon  the  principle  of  Scheiner's  experi- 
ment. The  conditions  precedent  to  the  appearance  of  this  symp- 
tom are  an  inaccurate  adjustment  of  the  eye  upon  the  point  fixed, 
and  the  existence  of  irregularities  in  the  structure  of  the  refract- 
ing media.  Monocular  polyopia  under  physiological  relations 
may  always  be  produced  experimentally.*  Under  pathological 
relations  it  is  principally  irregularities  in  the  cornea,  or  in  the 
iris  (coloboma,  or  defects  near  the  pupil),  or  in  the  lens  (cataracta 
incipiens,  or  luxation),  which,  in  connection  with  inaccurate 
optical  adjustment,  cause  polyopia. 

*  Comp.  Helmholtz  physiol.  Optik,  pag.  139. 


II. 

SPECTACLES,   OPHTHALMOSCOPE,   AND 
OPHTHALMOMETER. 


SPECTACLES. 


Spherical  lenses  are  those  most  frequently  employed.  Rules 
for  their  use  having  been  already  given,  it  remains  only  to  note 
their  most  elementary  optical  laws. 

SPHERICAL    LENSES. 

a.  Concave  Lenses. — Rays  of  light  which  fall  parallel  upon 
the  surface  of  a  concave  lens  diverge  after  refraction  as  if  they 
came  from  its  negative  focus.  Thus  a  virtual  diininished  image 
of  distant  objects  is  formed  in  the  focus  of  the  concave  lens. 
Rays  of  light  which,  proceeding  from  a  point  at  a  finite  dis- 
tance, fall  divergent  upon  the  surface  of  the  concave  lens,  after 
refraction  diverge  as  if  they  had  proceeded  from  a  point  within 
the  focus.  The  conjugate  focal  distances  are  calculated  by  the 
formula  i-  -|- 1=  —  ^. 

If,  for  example,  in  Fig.  14,  the  distance  of  the  negative  focus 

Fig.  14. 


{/)  be  12  inches  (f  =  — ^L),  and  the  distance  of  the  point  a, 
seen  through  tlie  concave  glass,  be  9  inches  (i  =  i),  then  the 
position  of  the  conjugate  focus  oc  is  determined  by  the  calculation 
a  =  — 7 —  h=  —  (-g-  +  T2)  =  —  ^'  That  is  to  say,  the  light,  after 
refraction  in  a  concave  lens,  diverges  as  if  it  had  proceeded  from 


88 


SPHERICAL    LENSES. 


a  point  5y  inches  distant, — that  is,  from  oc,  the  virtual  image  of 
the  point  a. 

If  tlie  far  point  of  the  myopic  eye  coincide  with  /,  and  the  near 
point  with  o:,  then  by  the  use  of  the  concave  lens  the  far  point  is 
removed  to  an  infinite  distance,  and  tlie  near  point  to  the  distance 
of  a.  The  virtual  images  of  all  objects  seen  distinctly  fall  be- 
tween oc  and  /.  No  virtual  image  can  be  formed  at  a  greater 
distance  than/,  because  the  image  of  an  object  at  an  infinite  dis- 
tance is  formed  at  /.  (For  convergent  rays  of  light  the  dispersion- 
point,  it  is  true,  would  lie  farther  distant  than  /.  We  may,  how- 
ever, for  the  present  neglect  this  case.) 

Virtual  images  which  lie  between  the  concave  glass  and  oc 
give  no  distinct  retinal  images,  because  the  accommodation  is 
insufficient,  a  being  the  near  point. 

Convex  Lenses. — Rays  of  light  which  fall  parallel  upon  the 
surface  of  a  convex  lens  converge,  after  their  refraction,  in  such  a 
manner  that  they  intersect  each  other  at  its  focus.  Rays  coming 
from  a  far-distant  object  may  be  regarded  as  parallel ;  after  refrac- 
tion they  accordingly  form  at  the  focal  distance  of  the  lens  an 
inverted  diminished  image.  If  a  luminous  point  lie  at  a  finite 
distance  from  the  convex  lens,  the  conjugate  focal  distance  is 
calculated  from  the  formula  -5  +  i^7- 

If,  in  Fig.  15,  the  distance  of  the  focus  /  be  4  inches,  and  the 

Fig.  15. 


object  a  be  placed  12  inches  distant,  then  the  image  oc  must  be 
formed  6  inches  beyond  the  lens,  since  ^  =  \ — iV^^  e-  The  image 
at  oc  is  inverted  and  diminished. 

Inversely:  if  the  rays  proceed  from  oc,  an  enlarged  inverted 
image  will  be  formed  at  a.  The  size  of  the  image  is  the  same  as 
that  of  the  object  when  the  object  is  placed  at  twice  the  focal 
distance  of  the  lens. 

If  the  luminous  point  be  at  the  focus,  the  rays,  after  refraction, 
are  parallel. 

If,  as  in  Fig.  16,  the  luminous  point  a  lie  between  the  focus 


SPHERICAL,    LENSES.  89 

and  the  lens,  the  rays,  after  refraction,  will  diverge  as  if  they 
came  from  oc,  a  point  lying  beyond  the  focus. 

Fig.  16. 


■■i -j{|-j{;£-:>>53gHs=»-oc 


In  the  formula  ^  +  a=7>  ^  becomes  a  negative  quantity, — that 
is,  a  virtual  image  is  formed.  For  instance,  if  the  focal  distance 
be  12  inches  and  the  object  be  placed  at  a  distance  of  8  inches, 
the  virtual  image  oc  will  be  formed  at  a  distance  of  24  inches. 

This  relation  is  illustrated  in  emmetropic  or  slightly  myopic 
eyes,  which,  on  account  of  presbyopia  or  paresis  of  accommoda- 
tion, require  the  use  of  convex  glasses.  Only  such  objects  as  lie 
at  or  within  the  focal  distance  can  be  distinctly  seen;  the  rays 
from  a  more  distant  object  converge  after  their  refraction  and 
intersect  each  other  before  reaching  the  retina. 

In  facultative  hypermetropia,  a  correcting  convex  glass  being 
used,  objects  placed  within  the  focus  can  be  distinctly  seen  up  to  a 
distance  determined  by  the  strength  of  the  accommodation.  All 
objects  lying  beyond  the  focus  can  also  be  distinctly  seen,  because 
such  eyes  can  accommodate  to  convergent  rays.  In  absolute  hyper- 
metropia only  objects  lying  beyond  the  focal  point  can  be  seen, 
because  such  eyes  are  adapted  only  to  convergent  rays. 

Biconcave  or  biconvex  lenses  are  the  ones  generally  used  for 
spectacles.  They  should  be  so  fixed  in  their  frames  that  the  centre 
of  the  lens  is  exactly  opposite  the  pupil.  Lenses  intended  for  use 
on  near  objects  must  therefore  have  their  optical  centres  somewhat 
nearer  together  than  those  to  be  used  upon  distant  objects ;  they 
must  also  be  so  inclined  to  each  other  that  their  axes  nearly  corre- 
spond to  the  convergence  of  the  visual  axes. 

Wollaston  recommended  the  so-called  periscopic  glasses.  These 
are  positive  or  negative  meniscuses, — that  is,  lenses  having  one 
concave  and  one  convex  surface  of  different  curvature.  They 
diminish  spherical  aberration.  In  weak  glasses  this  advantage 
is  of  little  importance,  and  in  strong  ones  it  is  greatly  over- 
balanced by  the  thickness  of  their  edges. 

7 


90  BIFOCAL    LENSES. 

Franklin  was  the  first  to  propose  an  arrangement  for  the  con- 
venience of  those  who  require  one  pair  of  lenses  for  near  and 
another  for  distant  objects.  He  placed  the  two  sets  of  lenses 
in  the  same  frame,  in  such  a  manner  that  in  the  case  of  convex 
glasses  one-half  of  a  weak  lens,  for  distant  objects,  is  in  the  upper 
part  of  each  frame,  and  one-half  of  a  stronger  one,  for  near 
objects,  is  in  the  lower  part.  For  concave  glasses  the  relative 
position  of  the  stronger  and  weaker  lenses  is  reversed.  Still 
better  are  the  glasses  of  double  focus  now  in  use.  The  upper  half 
is  so  ground  as  to  be  suitable  for  distant  objects ;  the  lower  half 
for  near  ones.  Such  glasses  are  especially  adapted  to  presbyopic 
hypermetropes,  since  the  slightest  movement  is  enough  to  adjust 
the  eye  either  for  near  or  distant  vision. 

CYLINDRICAL   LENSES. 

In  spherical  lenses  the  curved   surfaces   form   portions  of  a 

sphere ;  in  cylindrical  lenses  they  form  portions  of  a  cylinder. 

If  from  a  solid  glass  cylinder,  a  piece  be  cut  by  a  plane  parallel 

with  its  axis,  a  plano-convex  cylindrical  lens  is  obtained.     The 

figure  presented  by  the  cross-section  of  such  a  lens  is  the  segment 

of  a  circle,  bounded  on  one  side  by  the  arc,  on  the  other  by  the 

chord  (see  Fig.  17,  a).     The  figure  presented 

Fig.  17.  }jy  ^lie  section   of  such  a  lens    by  a  plane 

parallel  with    the  axis  of  the   cylinder,   is 

bounded  by  parallel  straight  lines  (Fig.  17,6). 

I7i         Rays  of  light  which  diverge  in  the  plane 

of  the  axis  are  therefore  refracted,  as  in  a 

^  plane   glass ;    while   rays  which   diverge  at 

Section  through  a  cyiin-     fig^t  anglcs  to  the  axis  experience  a  refrac- 

dricai  convex  glass :  «,  at     ^Jqu  Corresponding  to  the  radius  of  curvature. 

right  angles ;  6,  parallel  to  -^  i-ii  ^•      ^    •      ^  j 

the  axis  of  the  cylinder.  Lcuses  which  havc  two  cylmdricai  curved 

surfaces,  whose  axes  are  at  right  angles  to 
each  other,  are  called  bi-cylindrical  lenses.  If  in  this  case  the 
radii  of  the  two  curved  surfaces  be  equal,  and  both  surfaces  be 
either  concave  or  convex,  the  effect  is  the  same  as  that  of  a 
spherical  lens. 

Sphero-cylindrical  lenses  have  one  spherical  and  one  cylindrical 
curved  surface.  The  surfaces  may  be  both  concave,  or  both  con- 
vex, or  one  may  be  concave  and  the  other  convex. 


CYLINDRICAL    LENSES.  91 

Great  care  must  be  taken  in  setting  cylindrical  lenses  in  spec- 
tacle frames.  They  must  be  so  placed  that  the  axis  of  each  cyl- 
inder lies  in  the  plane  of  one  of  the  principal  meridians  of  the 
eye.  Supposing  the  principal  meridian  of  the  shortest  focal  dis- 
tance in  an  astigmatic  eye  to  be  vertical,  then  concave  cylindrical 
glasses  must  be  set  with  their  axes  horizontal,  and  convex  glasses 
with  their  axes  vertical. 

If  the  principal  meridians  are  neither  exactly  vertical  nor  hori- 
zontal, one  may  either  direct  the  optician  at  what  angles  he  must 
place  the  axes,  or  the  glasses  may  be  made  circular  and  so  set  as 
to  turn  in  their  frames.  The  proper  direction  for  the  axes  of  the 
cylindrical  lenses  may  then  be  found  experimentally.  If  the 
spectacles  are  to  be  used  principally  for  near  objects,  their  proper 
position  should  be  determined  by  testing  them  upon  objects  at  the 
usual  reading  distance. 

The  refraction  of  light  by  an  asymmetric  system  is  easily 
demonstrated  by  allowing  the  rays  from  a  luminous  point  to  pass 
through  a  strong  convex  lens  combined  with  either  a  cylindrical 
or  a  Stokes  lens,  and,  after  their  refraction  by  this  apparatus,  to 
receive  them  on  an  opaque,  ground-glass  plate.  The  shape  of  the 
image  formed  at  any  point  within  the  focal  interval  is  thus  beau- 
tifully shown. 

Light  is  refracted  in  a  similar  manner  in  spherical  lenses  whose 
axes  are  placed  at  an  inclination  to  the  direction  of  the  impinging 
rays.  In  cases,  therefore,  in  which  strong  spherical  lenses  are 
necessary,  for  instance  after  cataract  operation,  a  slight  degree  of 
astigmatism  may  be  corrected  by  giving  the  lenses  a  proper  incli- 
nation. 

PRISMATIC   SPECTACLES. 

Rays  of  light  on  passing  through  a  prism  are  refracted  toward 
its  base.  The  degree  of  their  refraction  increases  with  the  increase 
of  the  refracting  angle  of  the  prism,  and  with  the  refrangibility 
of  the  rays  themselves.  A  limitation  of  the  use  of  prismatic 
spectacles  is  thus  set,  both  by  the  diffusion  of  color  and  the  weight 
of  the  prisms.  There  is  no  difficulty  in  correcting  the  diffusion 
of  color  by  means  of  achromatic  ])risms ;  but  such  glasses,  being  a 
combination  of  two  prisms,  are  too  cumbersome  to  allow  their  use 
as  spectacles. 

Prisms  with  a  refracting  angle  greater  than  6°  can  hardly  be 


92 


PRISMATIC   SPECTACLES. 


used  as  spectacles.  At  about  this  limit  the  diffusion  of  color  and 
the  weight  of  the  glasses  begin  to  cause  inconvenience.  Prisms 
with  a  refracting  angle  greater  than  4°  are  seldom  used. 

The  advantage  derived  from  the  use  of  prisms  is,  that  they  unite 
double  images  when  not  widely  separated,  and  thus  prevent  the 
occurrence  of  diplopia.  For  example,  if  the  axis  of  vision  of  one 
eye  be  directed  exactly  upon  an  object,  and  if  the  axis  of  vision 
of  the  other  eye  deviate  outward  from  the  object,  the  image  in 
the  deviating  eye  will  fall  to  one  side  of  the  macula  lutea.  By 
the  choice  of  a  proper  prism  it  can,  however,  be  thrown  directly 
upon  it. 

Prisms  are  oftenest  used  where  there  is  insufficiency  of  the 
internal  recti  muscles.  They  unite  double  images  aiid  prevent 
diplopia. 

Fig.  18. 


In  Fig.  18,  suppose  the  point  a  to  be  placed  in  the  median 
plane  and  so  near  the  eyes  that  the  internal  recti  muscles  can 
direct  the  axes  of  vision  simultaneously  upon  it  but  are  unable  to 
hold  them  continuously  there.  Now,  if  we  place  before  each  eye 
a  prism  with  its  refracting  angle  turned  outward,  the  place  of  the 
retinal  imao;e  m  will  be  moved  to  m!  on  the  median  side  of  the 
macula  lutea.  Double  images  appear,  but  are  almost  immediately 
united,  as  the  cornea  turns  spontaneously  outward  and  the  macula 
lutea  inward.  Meanwhile  the  accommodation  remains  unchanged, 
and  is  directed  upon  the  distance  of  the  point  a,  while  the  axes  of 
vision  intersect  at  the  more  distant  point  a' . 

We  have  thus  substituted  prisms  for  the  action  of  the  recti 
interni  muscles,  just  as  convex  lenses  may  be  substituted  for  the 
action  of  accommodation.  But  while  the  use  of  convex  lenses 
presents  no  difficulties,  that  of  prisms  has  very  narrow  limits. 
How  much  now  can  be  accomplished  within  these  limits  ?     The 


PRISMATIC   SPECTACLES.  93 

answer  to  this  question  depends  upon  the  situation  of  the  far 
point.  The  nearer  the  point  upon  which  the  visual  axes  must 
converge,  the  less  the  effect  of  prisms.  The  minimum  of  devia- 
tion in  the  case  of  weak  prisms,  thus  employed,  is  equal  to  about 
half  their  refracting  angles;  for  stronger  prisms  it  is  somewhat 
more.  We  can  calculate  the  place  of  the  apparent  image  of  any- 
given  object  when  seen  through  prisms. 

A  myope,  without  the  help  of  concave  glasses,  can  get  no  dis- 
tinct image  of  an  object  lying  beyond  his  far  point.  If,  for 
instance,  his  far  point  be  100  mm.,  or  about  4  inches  distant, 
then  M  =  J.  If  convergence  upon  this  point  cannot  be  main- 
tained, the  point  of  intersection  of  the  axes  of  vision  can  be  re- 
moved farther  from  the  eyes  by  placing  in  front  of  each,  a  prism 
of  4°,  with  the  refracting  angle  turned  outward.  The  calcula- 
tion shows  that  the  point  of  intersection  is  thus  removed  15  mm. 
Instead  of  converging  upon  a  point  100  mm.  distant,  it  is  now^ 
necessary  to  converge  upon  a  point  115  mm.  distant  (less  than  4|^ 
inches).  But  it  is  still  questionable  whether  most  myopes,  under 
such  circumstances,  may  not  prefer,  in  place  of  so  inadequate  as- 
sistance, either  with  or  without  prismatic  spectacles,  to  renounce 
binocular  vision,  and  to  see  distinctly  with  relative  divergence  and 
monocular  vision. 

Even  with  stronger  prisms,  little  more  can  be  accomplished. 
Prisms  of  6°,  with  their  bases  turned  inward,  placed  before  each 
eye,  with  an  object  distance  of  4  inches,  remove  the  apparent  place 
of  the  image  only  to  4^  inches.  The  convergence  necessary  for 
binocular  vision  is  therefore  only  slightly  diminished. 

The  relations  are  more  favorable  when  it  is  possible  to  employ 
greater  distances.  An  object  being  10  inches  distant,  a  prism  of 
4°  before  each  eye  removes  the  apparent  place  of  the  image  toward 
which  the  visual  axes  must  converge  to  a  distance  of  12^  inches. 
If  now  it  is  wished  to  use  the  eyes  upon  work  at  a  distance  of  12 
inches,  these  same  prisms  make  it  possible  to  maintain  binocular 
fixation  with  a  convergence  of  the  visual  axes  of  not  more  than 
18  inches. 

Prismatic  spectacles  are  more  useful  the  greater  the  distance  of 
the  work  upon  which  they  are  employed.  For  this  reason,  in 
many  cases  of  myopia,  more  can  be  accomplished  with  concave 
prismatic  glasses  than  with  simple  prisms.     Such  glasses,  it  is 


94  PROTECTIVE    SPECTACLES. 

true,  always  give  somewhat  irregular  retinal  images,  on  account  of 
the  asymmetric  refraction  caused  by  the  inclined  position  of  the 
curved  surfaces. 

Convex  lenses  whose  axes  do  not  coincide  with  the  axes  of 
vision  act  as  sphero-prismatic  lenses.  The  degree  of  refraction 
which  they  cause  depends  on  the  focal  distance  of  the  lenses,  and 
the  degree  of  their  eccentricity.  If,  for  instance,  a  6-inch  convex 
lens  be  so  placed  in  spectacle  frames  that  its  optical  centre  is  ^  of 
an  inch  toward  the  median  line  of  the  visual  axis,  the  same  effect 
is  produced  as  by  combining  a  convex  lens  of  6  inches  focal  dis- 
tance witli  a  prism  of  4°,  with  its  refracting  angle  turned  out- 
ward. With  weaker  glasses  and  less  eccentricity  the  efiect  is 
naturally  slighter. 

STENOPAIC   APPARATUS. 

Donders's  stenopaic  apparatus  is  an  arrangement  by  Avhich  the 
rays  of  light  are  admitted  to  the  eye  only  through  a  small  circu- 
lar opening  or  a  very  narrow  slit.  It  is  an  indispensable  instru- 
ment in  diagnosticating  anomalies  of  refraction.  The  use  of  this 
apparatus  often  causes  a  marked  improvement  of  vision  in  cases 
of  cloudiness  of  the  cornea,  lens,  or  any  of  the  refracting  media. 
But  it  is  seldom  possible  to  wear  it  in  the  form  of  spectacles, 
because  the  field  of  vision  is  made  so  small.  It  is  most  applica- 
ble to  spectacles  which  are  used  on  near  objects. 

Donders  recommends  stenopaic  spectacles  in  cases  of  high 
degree  of  myopia  combined  with  loss  of  distinct  vision,  where 
the  proper  correcting  lenses  cause  only  slight  improvement  of 
vision  for  distant  objects,  because  the  retinal  images  are  rendered 
so  small.  Concave  glasses,  too  weak  to  fully  correct  the  myopia, 
give  larger  retinal  images ;  but  under  these  conditions  the  pupils 
are  quite  large,  and  the  circles  of  diifusion  are  correspondingly 
annoying.  A  combination  of  these  weak  lenses  with  a  stenopaic 
opening  of  about  1  mm.  diameter  lessens  the  size  of  the  circles 
of  diffusion  without  affecting  that  of  the  retinal  images. 

PROTECTIVE    SPECTACLES. 

Blue  or  smoke  glasses  are  the  best  to  protect  the  eyes  against 
dazzling  light.  In  order  to  protect  the  whole  field  of  vision  as 
uniformly  as  possible,  the  spectacles  should  be  shaped  like  watch- 
glasses,  or  else  be  provided  on  the  temporal  side  with  a  small 


PROTECTIVE    SPECTACLES.  95 

shade  of  silk  or  of  colored  glass.  If  this  precaution  be  not  ob- 
served, the  light  falling  upon  the  eyes  from  the  side  becomes  the 
more  annoying  the  darker  the  glass.  It  is  not  advisable  to  wear 
such  glasses  when  the  light  is  not  dazzling,  as  the  practice  rather 
tends  to  increase  the  sensitiveness  to  the  impression  of  light.  It 
must  also  be  remembered  that  the  darker  the  glasses  the  more 
heated  they  become  when  exposed  to  the  sun,  and,  consequently, 
the  more  hurtful  to  the  eyes. 

THE   OPHTHALMOSCOPE. 

In  the  ophthalmoscopic  illumination  of  the  eye,  the  first  con- 
dition to  be  fulfilled  is  that  light  shall  be  thrown  into  it  in  the 
direction  of  the  visual  axis  of  the  observer. 

The  construction  of  the  various  ophthalmoscopes  by  which  the 
fundus  of  the  eye  is  illuminated  will  be  briefly  explained  in  the 
latter  part  of  this  section.  They  have  all  the  common  object  to 
cast  upon  the  fundus  of  the  eye  either  a  distinct  or  a  diffuse  image 
of  the  light  used  for  illumination.  This  being  accomplished,  we 
must  next  see  wdiat  happens  with  the  rays  which  have  been  united 
upon  the  fundus  and  have  there  formed  an  image  of  the  light. 
Part  of  them  are  absorbed  by  the  pigment  in  the  fundus ;  the 
remainder  are  reflected  diffusely,  and  a  part  of  these  thus  diffusely 
reflected  rays  pass  out  of  the  eye,  through  the  pupil,  through  the 
ophthalmoscope,  and  into  the  eye  of  the  observer.  To  him,  there- 
fore, the  pupil  of  the  eye  examined  appears  brightly  illuminated. 

What  now  is  the  exact  direction  of  the  rays  reflected  from  the 
fundus  of  the  eye  after  they  emerge  from  the  refracting  media? 
This  question  can  be  easily  answered  so  soon  as  we  know  the  posi- 
tion of  the  fundus  in  relation  to  the  focus  of  the  refractine;  media. 
If,  as  in  the  emmeti'opic  eye,  the  length  of  the  visual  axis  equal 
the  focal  length  of  the  dioptric  appa- 
ratus, then  will  the  rays  from  each  ^^-  ^^• 
illuminated  point  in  the  fundus, 
after  their  exit  from  the  refract- 
ing media,  form  a  parallel  beam. 
Since,  for  example  (as  in  Fig.  19), 

rays  of  light  which  fall  parallel  upon  the  schematic  eye  are,  after 
their  refraction,  focused  upon  the  fundus  at  '/*;  conversely,  rays 
which  proceed  from  r,  after  their  exit  from  the  eye,  are  parallel. 


96  OPHTHALMOSCOPE,  UPRIGHT  IMAGE. 

If  now  the  observer  be  emmetropic,  these  parallel  rays  falling 
upon  his  cornea  will  be  focused  upon  his  retina.  For  each  point 
of  the  fundus  of  the  examined  eye  he  will  receive  a  distinct  reti- 
nal image;  that  is  to  say,  he  can  see  the  fundus  without  any 
further  optical  aid. 

The  dioptric  apparatus  of  the  eye  examined,  serves  the  observer 
just  as  a  lens,  by  means  of  which  he  can  see  an  object  (in  this  case 
the  fundus)  placed  at  its  focus.  The  lens  gives,  under  these  cir- 
cumstances, an  upright,  enlarged  image,  and  for  that  reason  this 
kind  of  ophthalmoscopic  examination  is  called  "the  examination 
in  the  upright  image." 

Later  we  will  speak  of  the  modification  of  this  examination  in 
cases  where  the  observer  is  not  emmetropic.  For  the  present,  to 
avoid  complication,  we  will  suppose  him  to  be  so. 

The  most  favorable  condition  under  which  to  see  an  object 
at  the  focal  distance  of  a  lens  is  to  place  our  own  eye  as  near  as 
possible  to  the  lens.  Only  under  this  condition  do  we  have  the 
field  of  vision  in  its  greatest  extent.  As  we  increase  the  distance 
between  our  eye  and  the  lens,  there  is  only  an  apparent  enlarge- 
ment of  the  image;  simultaneously,  however,  the  size  of  the  visual 
field  is  rapidly  diminished. 

It  follows,  therefore,  that  to  examine  the  fundus  of  an  emme- 
tropic eye  in  the  upright  image  the  examiner  must  place  his  own 
eye  as  near  as  possible  to  it.  If  he  place  his  own  eye  at  too  great 
a  distance,  the  field  of  vision  becomes  so  contracted  that  small 
objects,  no  broader  than  a  retinal  vessel,  entirely  fill  it.  It  is 
no  longer  possible  to  obtain  a  complete  and  distinct  view  of  the 
fundus. 

The  size  of  the  visual  field  is  always  somewhat  smaller  than 
the  pupil  of  the  eye  under  examination.  It  is,  moreover,  some- 
what obscured  by  the  unavoidable  corneal  reflex.  A  second  essen- 
tial condition  to  be  fulfilled  is,  that  the  observer  relaxes  fully  his 
accommodation,  so  that  his  eye  is  adjusted  for  parallel  rays.  The 
same  applies  to  the  eye  under  examination.  Their  nearness  to 
each  other  causes  a  tendency,  both  in  the  examined  eye  and  in 
that  of  the  examiner,  to  involuntary  accommodation.  This  may 
be  avoided  on  the  part  of  the  patient  by  directing  his  attention 
upon  some  distant  object.  The  examiner  must,  however,  learn 
without  any  such  help  to  avoid  all  accommodation.     If  he  cannot 


OPHTHALMOSCOPE,  UPRIGHT    IMAGE. 


97 


do  this,  he  is,  during  an  ophthalmoscopic  examination,  in  the 
same  condition  as  a  myope,  and  must  make  use  of  the  same  means 
of  correction. 

If  the  eye  under  examination  be  myopic,  the  relations  are  those 
shown  in  Fig.  20. 

Fig.  20. 


Rays  which  fall  parallel  upon  the  cornea  are  focused  at  (p  in 
front  of  the  retina.  In  order  to  cast  its  image  upon  the  retina, 
the  luminous  point  must  approach  the  eye  to  the  point  r.  Then 
rays  of  light  which  diverge  from  the  point  r'  within  the  eye  will, 
after  their  exit  from  it,  converge  toward  the  point  r. 

Assuming  entire  relaxation  of  accommodation,  the  rays  of  light 
which  diverge  from  the  fundus  of  a  myopic  eye  will  be  focused 
at  the  far  point  of  the  eye.  At  this  distance  an  enlarged  inverted 
image  of  the  fundus  is  formed.  In  the  ophthalmoscopic  exami- 
nation of  a  myopic  eye,  the  rays  emerge  from  it  in  converging 
beams,  and  they  cannot  be  united  in  a  distinct  retinal  image  in 
the  eye  of  an  emmetropic  observer.  He  will  accordingly  see  the 
fundus  of  the  myopic  eye  only  in  indistinct  outlines.  In  order 
to  get  a  distinct  image  the  convergent  beams  must  be  converted 
into  parallel  ones. 

In  Fig.  21,  let  A  be  the  myopic  eye  under  examination,  and  B 
the  emmetropic  eye  of  the  observer  adjusted  for  parallel  rays. 

Fig.  21. 


4s3«>K"--— a' 


The  rays  from  the  point  a  of  the  eye  A  will  intersect  at  the  far 
point  a' .  Suppose  this  distance  to  be  10  inches  (1X1  =  315-).  If 
now  there  be  placed  in  front  of  the  eye  B  a  concave  lens  of  such 
a  power  that  its  negative  focus  coincides  with  the  point  a',  then 
the  rays  which  fall  convergently  upon  it  will  be  refracted  into 
13arallel  ones,  and  will  consequently  form  a  distinct  retinal  image 
in  the  eye  B.     If  the  distance  between  the  concave  glass  and  the 


98 


OPHTHALMOSCOPE,  UPRIGHT    IMAGE. 


eye  A  be  2  inches,  the  concave  lens  must  have  a  focal  distance 
of  8  inches.  The  fundus  is  seen  just  as  is  an  object  through  a 
Briicke  lens.  The  convex  glass  of  the  instrument  corresponds 
with  the  refracting  apparatus  of  the  myopic  eye,  while  the  ocular 
corresponds  with  the  concave  glass  in  front  of  the  eye  of  the 
observer. 

It  follows  from  what  has  been  said  that  in  high  degrees  of 
myopia  the  image  may  be  formed  within  a  very  few  inches  of  the 

Fig.  22. 


eye.  If,  for  instance,  in  Fig.  22,  the  far  point  r  of  the  eye  be  at 
a  distance  of  3  inches,  an  inverted  enlarged  image,  n',  will  be 
formed  at  that  distance.  The  observer,  whose  axis  of  vision  is 
directed  upon  n,  needs,  in  order  to  see  the  image  at  7i',  only  to 
withdraw  so  far  from  it  that  he  can  accommodate  his  eye  upon  it, 
or  he  may  use  a  weak  convex  lens,  say  -f-  -^.  He  can  thus  get 
an  inverted  enlarged  view  of  any  part  of  the  fundus.  If  the  ob- 
server approaches  the  observed  eye,  the  inverted  image  becomes 
indistinct  so  soon  as  it  comes  to  lie  between  the  observer's  eye 
and  his  near  point.  As  he  approaches  still  nearer  it  becomes 
unrecognizable. 

The  extent  of  the  visual  field  depends  upon  the  size  of  the  pupil 
of  the  eye  observed.  But  even  with  the  pupil  fully  dilated  it 
must  always  be  rather  small,  since  the  distance  between  the  ex- 
aminer's and  the  examined  eye  must  necessarily  be  from  8  to  12 
inches. 

If  the  examined  eye  is  hypermetropic, — that  is,  if  the  fundus  lie 

Fig.  23. 


a'' 


in  front  of  the  focus  of  the  dioptric  apparatus, — then  will  the  light 
reflected  from  a  (Fig.  23)  diverge,  after  its  exit  from  the  eye,  as  if 


OPHTHALMOSCOPE,  UPEIGHT    IMAGE.  99 

it  had  proceeded  from  the  point  a' .  In  this  examination  the  re- 
lations are  the  same  as  if  we  were  examining  the  fundus  Avith  a 
lens  which  relatively  to  its  focal  distance  had  approached  too  near 
the  eye,  or,  in  other  words,  as  if  we  were  examining  with  too 
weak  a  lens.  Under  these  conditions  the  enlargement  diminishes, 
while  the  extent  of  the  field  increases.  In  emmetropia  we  Avere 
always  compelled  to  approach  as  near  as  possible  in  making  our 
examination,  because  upon  withdrawing  from  the  eye  the  field  of 
vision  diminished  so  rapidly  that  soon  even  the  smallest  objects 
could  not  be  seen.  This  disadvantage  becomes  less  in  hyperme- 
tropia,  and  this  is  the  reason  for  the  easily  observed  and  charac- 
teristic phenomenon,  that  immediately  upon  making  the  ophthal- 
moscopic examination  the  observer  sees  the  various  parts  of  the 
fundus  in  an  upright  enlarged  image.  Since  the  place  of  this 
image  is  behind  the  eye  under  examination,  the  observer  must  reg- 
ulate his  accommodation  accordingly.  Upon  approaching  the  eye 
the  size  of  the  visual  field  increases,  but  it  can  happen  only  in  cases 
of  the  highest  degree  of  hypermetropia,  in  AA^hich  the  far  point 
lies  only  a  few  inches  behind  the  eye,  that  the  image  becomes  in- 
distinct, by  reason  of  its  lying  within  the  near  point  of  the  observer. 

Instead  of  employing  his  accommodation,  it  is  in  general  better 
for  the  observer  to  use  a  convex  lens.  The  lens  should  be  so 
chosen  that  its  focus  coincides  Avith  the  far  point  of  the  examined 
eye.  If  Avith  his  own  eye  placed  as  near  as  possible  to  the  exam- 
ined eye  the  observer  can  still  see  the  details  of  the  fundus  through 
a  convex  lens,  hypermetropia  exists. 

All  the  rules  Avhich  have  been  given  are  equallj^  applicable  to 
the  case  of  an  examiner  Avho  is  not  emmetropic,  provided  he  first 
correct  his  ametropia  by  a  suitable  lens. 

To  examine  an  emmetropic  eye  in  the  upright  image,  a  myope 
must  use  a  concave  lens  which  fully  neutralizes  his  myopia,  Avhich 
places  his  far  point  at  an  infinite  distance,  in  short,  Avhich  makes 
the  relations  the  same  as  in  emmetropia.  A  fact  may  here  be 
mentioned  Avhich  Helmholtz*  first  called  attention  to.  It  is  this, 
that  an  emmetrope  requires  a  somcAvhat  stronger  concave  lens  to 
see  the  fundus  of  a  myopic  eye  than  does  a  myoi)e  to  see  the 
fundus  of  an  emmetropic  eye.     As  already  shoAvn  in  Fig.  21,  the 

*  Beschreibung  eines  Augenspiegels,  1851,  pag.  24. 


100  OPHTHALMOSCOPE,  UPRIGHT    IMAGE. 

focal  distance  of  the  lens  used  by  the  emmetropic  observer  must 
be  shorter  than  that  used  by  a  myopic  observer  by  a  distance  equal 
to  that  at  which  the  eyes  are  held  from  each  other  during  the 
examination. 

In  examining  a  myopic  eye,  a  myope  must  correct  by  the  use 
of  a  concave  lens  not  only  his  own  myopia  but  that  of  the  patient. 

A  myope  may  examine  a  hypermetropic  eye  without  concave 
glasses,  provided  the  hypermetropia  be  somewhat  greater  than 
his  own  myopia.  If  the  hypermetropia  be  less,  the  myope  will 
require  a  concave  lens  which  will  remove  his  far  point  till  it 
coincides  with  that  of  the  hypermetropic  eye. 

A  hypermetrope  can  examine  an  emmetropic  eye  with  his  own 
correcting  glasses.  For  a  degree  of  myopia  somewhat  less  than 
his  own  hypermetropia,  he  requires  no  correcting  glasses.  If  the 
myopia  is  greater  than  his  own  hypermetropia,  he  must  by  the 
use  of  a  concave  lens  so  change  the  direction  of  the  convergent 
rays  from  the  myopic  eye  that  they  shall  converge  toward  his 
own  far  point.  For  a  hypermetrope  to  examine  a  hypermetropic 
eye  in  the  upright  image,  he  must  either  accommodate  strongly  or^ 
use  convex  glasses. 

EXAMINATION    IN    THE    INVERTED    IMAGE. 

We  will  suppose  the  fundus  of  the  eye  in  Fig.  24  to  be  illumi- 
nated, and  that  the  rays  emerging  from  the  pupil  are  received  by 
the  convex  lens  c;  then,  according  to  known  laws,  will  the  rays  pro- 
ceeding from  a  be  again  united  at  the  point  a'.     If  the  eye  under 

Fig.  24. 


examination  be  emmetropic,  so  that  the  rays  of  light  upon  emerging 
from  the  pupil  are  parallel,  then  will  the  point  a'  coincide  with 
the  principal  focus  of  the  convex  lens.  If  the  eye  be  myopic,  the 
rays  fall  converging  upon  the  convex  lens,  and  the  point  a'  will 
lie  nearer  to  it  than  its  principal  focus ;  in  hypermetropia,  where 
the  light  diverges  from  the  eye,  the  point  a'  will  lie  beyond  the 
principal  focus.     The  position  of  the  point  b'  is  found  in  the  same 


OPHTHALMOSCOPE,  INVEETED   IMAGE.  101 

way.  The  direction  of  the  rays  proceeding  from  6  is  determined 
by  a  line  which,  proceeding  from  the  point  6,  intersects  the  line 
a  a'  at  the  nodal  point  of  the  eye.  One  of  the  rays  belonging  to 
this  beam  will  pass  through  the  nodal  point  of  the  lens  c,  and  is 
therefore  the  axial  ray  upon  which  all  the  rays  belonging  to  this 
beam,  which  are  refracted  in  the  lens,  are  united  (for  instance, 
at  b'). 

It  is  evident  that  the  inverted  image  is  so  much  the  greater  the 
greater  its  distance  from  the  convex  lens,  since  the  farther  a'  is 
removed  the  greater  will  be  the  distance  between  a'  and  h' . 

Now,  in  order  to  see  distinctly  the  inverted  image  cast  in  this 
manner,  the  observer  has  only  to  take  care  that  his  line  of  vision 
coincides  with  the  line  a  a'  and  that  his  accommodation  is  adjusted 
upon  the  image  a'  h' . 

The  size  of  the  field  of  vision  in  the  examination  in  the  inverted 
image  depends  on  the  size  of  the  pupil  in  the  eye  under  examina- 
tion and  on  the  focal  length  of  the  convex  lens ;  the  shorter  its 
focal  distance,  the  less  the  enlargement  and  the  greater  the  field 
of  vision.  A  proper  holding  of  the  convex  lens  is  of  great  im- 
portance. Its  distance  from  the  eye  under  examination  should 
be  about  that  of  its  focal  length.  If  the  convex  lens  be  so  held 
that  rays  of  light  which  fall  parallel  upon  it  are,  after  their  re- 
fraction, united  exactly  at  the  plane  of  the  pupil  of  the  eye  under 
examination,  then,  conversely,  will  rays  of  light  diverging  from 
every  point  in  the  plane  of  the  pupil,  after  their  refraction  in  the 
convex  lens,  become  parallel.  In  this  case  the  image  of  the  pupil 
cast  from  the  convex  lens  attains  its  greatest  dimensions ;  since  it 
lies  at  an  infinite  distance  it  will- be  infinitely  large.  If  the  con- 
vex lens  be  held  too  near  the  eye,  it  casts  a  virtual  image  of  the 
iris ;  if  too  far,  a  real  image.  In  both  cases  the  field  of  vision  is 
diminished. 

SIZE    OF   THE   OPHTHALMOSCOPIC    IMAGE. 

We  base  our  discussion  of  the  size  of  the  ophthalmoscopic 
image  upon  Listing's  schematic  eye  as  reduced  by  Donders.* 
The  entire  dioptric  apparatus  is  here  represented  by  one  curved 
surface  l)ounded  in  front  by  atmospheric  air,  behind  by  tlie 
aqueous  humor,  and  whose  radius  of  curvature  is  5  millimetres. 

*  L.  c,  pag.  149. 


102  SIZE   OF    THE   OPHTHALMOSCOPIC    IMAGE. 

The  point  c,  Fig.  25,  lying  5  millimetres  behind  the  point  h  of  the 
curved  surface,  is  the  optical  centre.  The  index  of  refraction  is  =f . 
Rays  of  light  which  fall  parallel  upon  the  anterior  curved  surface 
are  united  in  the  second  medium  at  f" ,  20  millimetres  behind  li ; 
the  length  of  the  axis  of  vision  is  20  millimetres,  and  the  distance 
c  (p"  must  consequently  be  1 5  millimetres.  In  making  the  ophthal- 
moscopic examination,  we  place,  as  in  Fig.  25,  two  emmetropic  eyes 
„      25  opposite  each  other.     It  is  plain 

that  all  the  rays  of  light  proceed- 
ing from  the  point  a  in  the  eye  A 
will,  after  emerging  from  it,  form 
a  beam  whose  direction  is  deter- 
mined by  the  axial  ray  a  c.  One 
of  the  rays  belonging  to  this  beam  striking  the  eye  B  will  be 
directed  upon  the  nodal  point  k  of  this  eye,  and  will  consequently 
pass  through  it  unrefracted,  forming  the  axial  ray,  upon  which 
all  the  rays  proceeding  from  a  will  intersect ;  oc  will  consequently 
be  the  optical  image  of  the  point  a.  Since  upon  our  supposition 
the  lines  a  c  and  oc  k  are  parallel,  the  angles  a  c  0"  and  oc  ^y  will 
be  equal. 

An  immediate  consequence  of  our  supposition  is  that  the  image 
and  the  object  have  the  same  size ;  or  in  this  particular  case  the 
optic  disc  of  the  eye  A  casts  in  £  a  retinal  image  exactly  as  large 
as  itself.  Tlie  distance  between  the  two  eyes  has  no  effect  on  the 
size  of  the  image :  it  is  plain,  however,  that  the  field  of  vision 
becomes  smaller  the  more  A  and  B  are  removed  from  each  other. 
Under  what  angle  now  does  the  optic  disc  of  the  eye  A  appear 
to  the  eye  B  f  Evidently  it  is  the  angle/  Z;  oc,  which  we  call  the 
angle  of  vision.  Its  size  is  easily  calculated.  Vi.  k  j  =■  c  fp"  =■ 
15  millimetres,  and  if,  for  simplicity,  we  call  the  diameter  of  the 
optic  disc  1.5  millimetres,  then  the  angle  of  vision  expressed  in 
terms  of  the  arc  of  a  circle  =  \^,  or  in  degrees  Yzk^T^  ^  180° 
=  5.73°. 

What  now  are  the  relations  when  the  eye  A  is  not  emmetropic? 
If  A  be  myopic  in  consequence  of  elongation  of  its  axis,  and 
if  its  far  point  lie^  for  instance,  139.5  mm.  in  front  of  k  (that  is, 
myopia  of  about  ^),  we  can  find  the  length  of  its  axis  by  calcu- 
lating, with  reference  to  such  a  far  point,  the  conjugate  focus  in 
the  eye  B,  whose  curved  surfaces  of  course  remain  unchanged. 


SIZE    OF    THE    OPHTHALMOSCOPIC   IMAGE.  103 

The  formula  for  the  calculation  is  7=^^  —  4?*  in  which  F  is 
the  conjugate  focal  distance  sought,  y"  the  principal  focal  distance 
=  20  ram.,  n  the  index  of  refraction  =  -|,  and  a  the  distance  of  the 
object  from  the  anterior  curved  surface  /i  =  134.5  mm.  This 
calculation  shows  an  increase  in  the  axis  of  2.5  mm. 

In  Fig.  26  the  eye  A  has  an  axis  of  22.5  mm.,  and  did  not  the 

emmetropic  eye  of  the  observer  intervene,  the  .object  a  b  would 

cast  its  enlarged  inverted  image  a'  b'  at  a  distance  of  139.5  mm. 

from  h. 

Fig.  26. 


All  the  rays  converging  toward  a  become  parallel  after  passing 
through  the  concave  glass  c,  provided  the  negative  focal  point  of 
c  coincide  with  a'.  Further,  one  of  the  rays  converging  toward 
b'  will  pass  through  the  optical  centre  of  the  concave  lens  c,  and 
will  indicate  the  direction  of  the  parallel  beam,  into  which  all  the 
rays  converging  toward  b'  have  been  converted. 

We  need  only  draw  through  ¥ ,  the  optical  centre  of  the  eye 
B,  a  line  parallel  to  the  line  c  b'  to  obtain  the  axial  ray,  upon 
which  the  image  of  b'  (/5)  is  formed. 

The  angle  cp"  k'  /5  is  therefore  the  visual  angle  under  which  the 
object  a  b  is  seen  ophthalmoscopically,  and  we  will  in  future  desig- 
nate it  by  the  letter  d.  It  is  evident  from  the  figure  that  the  size 
of  this  angle  depends  on  the  distance  of  the  concave  glass  c  from 
the  eye  A.  The  more  the  concave  glass  approaches  the  image 
a'  b',  so  much  the  shorter  is  its  conjugate  focal  distance,  so  much 
the  greater  becomes  the  angle  b'  c  a',  which,  as  a  parallel  angle, 
is  equal  to  the  angle  d,  so  much  the  greater  is  the  image,  but  so 
much  the  smaller  is  the  field  of  vision.  The  conditions  are  simi- 
lar to  those  in  a  Briicke  lens  or  a  Galilean  telescope.  It  is  only 
necessary  in  Fig.  26  to  substitute  a  convex  lens  for  the  eye  A.  In 
the  Galilean  telescope  the  principal  focus,  and  in  Briicke's  lens 

*  Comp.  Wiillner,  Einleitung  in  die  Dioptrik  des  Auges,  pag.  12. 


104  SIZE    OF    THE   OPHTHALMOSCOPIC    IMAGE. 

the  conjugate  focus,  with  reference  to  the  object  distance,  coincide 
with  a' :  the  rest  is  unchanged. 

The  value  of  the  angle  d  is  determined  by  the  following  calcula- 
tion. As  already  said,  d  =  angle  a'  c  b' ;  consequently,  expressed 
in  terms  of  the  arc  of  a  circle,  d  =  '^'. 

'  a'  c 

The  value  of  a'  h'  is  determined  from  the  proportion  a'  b'  : 
ab  :  :  a'  k  :  ah.  Now,  a  h^^^h  a  —  h  k, — that  is,  =  22.5  —  5 
=  17.5  mm.  «'  k=  139.5  mm.  Then,  taking  from  the  above  ab  = 
1.5  mm.,  we  have  a'  b'  =  ^-^^-yt.-§-^'--,  consequently  d=  Lii^J-??^, 
or  expressed  in  degrees,  d  =  --—-^——^—  X  180°. 

^  =>  '  a'cX  1  7-5  X3-14 

The  size  of  the  visual  angle  under  which  the  optic  nerve  of 
the  eye  A  appears  depends  upon  the  distance  of  the  correcting 
concave  glass  from  the  eye  under  examination,  always  provided 
that  the  negative  focal  distance  of  the  lens  coincides  with  the  far 
point  of  the  eye. 

If  we  hold  a  concave  lens  of  124.5  mm.  focal  length  in  front 
of  the  mirror  at  the  same  distance  as  that  at  which  a  spectacle- 
glass  is  generally  worn,  that  is,  15  mm.  from  k,  the  value  of  the 
angle  d  =  5.4°.  But  if  we  place  the  concave  lens  behind  the 
mirror  so  that  its  distance  is  50  mm.  from  k,  the  optical  centre  of 
the  examined  eye  A,  its  focal  distance  must  be  89.5  mm.,  and  the 
angle  d  is  then  =7.4°. 

If  the  diagrammatic  eye,  while  retaining  an  axis  of  20  mm.,  be 
adjusted  for  a  distance  of  139.5  ram.  by  a  change  of  curvature,  it 
will  have,  according  to  Bonders,*  a  radius  of  curvature  of  4.5  mm., 
consequently  a  k  will  equal  15.5  mm. 

Substituting  this  value  in  the  above  formula,  in  an  ophthalmo- 
scopic examination  with  a  concave  lens  of  164.5  mm.  focal  length, 
held  at  a  distance  of  15  mm.  from  ^•,  the  optic  nerve  would  appear 
under  an  angle  of  5.7°  ;  if,  however,  we  use  a  concave  lens  of  89.5 
mm.  focal  length  at  50  mm.  from  k,  the  visual  angle  =  8.59°. 

The  angle  under  which  the  optic  disc  appears  in  hypermetropia 
may  be  calculated  in  an  analogous  manner.  We  will  suppose  the 
axis  of  our  diagrammatic  eye  to  be  shortened  by  2  mm.  Then 
the  distance  ak:=lS  mm.  We  have  first  to  calculate  toward 
what  point  behind  k  rays  of  light  must  converge  in  order  to  be 

*  L.  c,  pag.  152. 


SIZE   OF   THE   OPHTHALMOSCOPIC  IMAGE.  105 

focused  at  a.  We  employ  in  this  calculation  the  same  formula  as 
we  have  used  above  in  computing  the  increase  of  the  axis  of 
vision  in  myopia,  namely,  7  +^^  ^,  in  which  a  represents  the 
distance  of  the  illuminated  point  from  k;  F  its  conjugate  focal 
distance  (A  a  =18  mm.);  fp"  the  focal  distance  for  parallel  rays 
{h  <p"  =20  mm.);  and  n  the  index  of  refraction  =  1^.  Since  we 
know  the  value  of  all  the  quantities  except  a,  the  formula  becomes 

inn 
"a  (pll  f' 

From  the  calculation  we  find  a  =  135.4  behind  h,  or  130.4 
behind  k  ;  we  have  very  nearly  Hi. 

The  relations  are  analogous  to  those  in  myopia,  only  reversed. 
The  image  of  the  optic  disc  cast  from  the  refracting  media  is  a 
virtual  one,  and  lies  130.4  mm.  behind  h.  In  order  to  convert 
the  rays  proceeding  from  this  virtual  image  into  parallel  ones  we 
need  a  convex  lens  whose  focal  distance  must  be  shorter  the 
nearer  we  bring  it  to  the  eye  under  examination,  and  consequently, 
also,  the  visual  angle  becomes  smaller  the  farther  we  remove  the 
correcting  convex  lens  from  the  eye  examined.  If  we  hold  it  in 
front  of  the  mirror  15  mm.  from  the  optical  centre  of  the  eye 
examined,  we  have  for  the  optic  disc,  whose  diameter  as  above  =  15 
mm.,  a  visual  angle  of  7.73°.  If,  on  the  contrary,  we  place  the 
correcting  convex  lens  behind  the  mirror,  50  mm.  from  the  optical 
centre  of  the  eye  examined,  the  visual  angle  diminishes  to  4.76°. 

But  if,  on  the  contrary,  a  diagrammatic  eye  with  an  axial  length 
of  18  mm.  accommodate  itself  for  parallel  rays,  this  involves  a 
shortening  of  the  radius  of  curvature  to  4.5  mm.  If  now  we  ex- 
amine the  eye  ophthalmoscopically  in  this  condition, — that  is,  when 
the  hypermetropia  of  \  has  been  neutralized  by  an  eifort  of  ac- 
commodation,— we  of  course  need  no  correcting  lens,  since  the  rays 
of  light  reflected  from  the  fundus  already  emerge  parallel  from 
the  refracting  media.  The  optic  disc  appears  therefore  under  a 
visual  angle  of  6.3°. 

Accordingly,  an  optic  disc  having  a  diameter  of  1.5  mm.  appears 
as  follows : 

a.  In  emmetropia  under  a  visual  angle  d  of  5.7°, 

6.  In  myopia  with  a  fiir  point  139.5  mm.  distant, — that  is, 
about  M|^, — 

1,  with  concave  124.5  mm.  at  a  distance  of  15  mm.,  cZ  ^5.4°  ; 

2,  with  concave  89.5  mm.  at  a  distance  of  50  m:n.,  cZ^7.4°. 


106  SIZE   OF  THE   OPHTHALMOSCOPIC  IMAGE. 

b'.  With  tlie  same  degree  of  apparent  myopia, 

1,  with  concave  124.5  mm.  at  15  mm.,  d  =  5.7°  ; 

2,  with  concave  89.5  mm.  at  50  mm.,  d=  8.59°. 

c.  In  hypermetropia  with  a  negative  far  point  130.4  mm. 
distant, — that  is,  about  H^, — 

1,  with  convex  145.4  mm.  at  a  distance  of  15  mm.,  d=  5.7°  ; 

2,  with  convex  186.4  mm.  at  a  distance  of  50  mm.,  d=  4.76°. 
c' .  In  the  same  degree  of  hypermetropia,  which,  however,  is 

latent  through  tension  of  accommodation,  d=  6.3°. 

These  results  agree  with  those  of  Mauthner.*  Still,  I  am  in- 
clined to  doubt  the  conclusions  which  others  have  drawn  from 
these  calculations.  It  would  certainly  be  an  interesting  fact  if  we 
could  determine  from  the  size  of  the  ophthalmoscopic  image 
whether  we  had  to  do  with  actual  or  with  only  apparent  emme- 
tropia, — that  is,  with  latent  hypermetropia ;  and  so,  too,  whether 
we  had  to  do  with  actual  or  with  apparent  myopia, — that  is,  spasm 
of  accommodation. 

In  the  first  place,  the  question  must  be  answered  whether  the 
optic  disc  may  be  regarded  as  of  an  invariable  size,  since,  of 
course,  the  size  of  the  ophthalmoscopic  image  depends  upon  the 
actual  size  of  the  disc.  In  this  matter,  however,  it  is  certain  that 
there  are  individual  variations.  According  to  Henle,t  for  instance, 
the  optic  nerve  in  the  plane  of  the  choroid  has  a  diameter  varying 
from  1.2  to  1.6  mm.  If  we  substitute  these  values  for  the  1.5 
mm.  assumed  in  the  original  calculation,  the  optic  disc  would  be 
seen  in  the  diagrammatic  eye  under  an  angle  varying  from  4.5° 
to  6°.  The  difference  is  1.5°, — that  is,  nearly  as  great  as  the  dif- 
ference between  the  visual  angles  in  manifest  H^,  examined  with 
convex  ^  at  2  inches  from  the  eye,  and  the  same  degree  of  hyper- 
metropia masked  by  the  accommodation.  In  such  a  case  we  should 
be  doubtful  whether  we  had  before  us  an  anatomically  large  or 
small  optic  disc,  or  one  more  or  less  magnified  for  optical  reasons. 
This  must  still  more  be  the  case  in  slight  degrees  of  hyperme- 
tropia. Cases  where  hypermetropia  of  ^  remains  wholly  latent 
are  very  infrequent. 

In  myopia,  moreover,  the  enlargement  increases  in  very  rapid 


*  Lehrbuch  tier  Ophthalmoscopie,  pag.  186. 
I  Anatomic,  ii.  pag.  586. 


SIZE    OF    THE   OPHTHALMOSCOPIC    IMAGE.  10l7 

progression  as  the  correcting  lens  is  withdrawn  from  the  eye.  The 
most  certain  method,  that  of  Coccius,  is  to  hold  the  correcting  lens 
close  to  the  eye  under  examination;  but  just  in  that  case  the 
difference  between  the  images  in  apparent  myopia  and  in  actual 
myopia,  caused  by  elongation  of  the  eye,  is  least  apparent. 

Still  more  important  is  the  fact  that  we  possess  no  means  of 
measuring  the  size  of  the  upright  image,  but  can  only  estimate  it 
approximately.  The  errors  likely  to  be  made  under  such  circum- 
stances may  be  shown  by  a  simple  experiment.  Any  object,  say 
the  smallest  size  of  ordinary  print,  is  placed  at  the  focus  of  a 
convex  lens,  provided  with  a  diaphragm,  which  must  not  be  too 
small.  If  now  the  observer  place  his  eye  close  to  the  lens,  he 
perceives  a  visual  field  of  a  certain  extent,  and  the  abjects  in  it 
magnified  to  a  certain  size.  If  now  he  withdraw  his  eye  from  the 
lens,  he  can  scarcely  avoid  the  impression  that  the  objects  become 
more  magnified.  Evidently  this  is  an  optical  illusion,  based  upon 
the  fact  that  the  relations  between  the  enlargement  of  the  objects 
and  the  size  of  the  visual  field  change  to  the  disadvantage  of  the 
latter.  The  object  portrayed  upon  the  retina  of  the  observer  is,, 
however,  the  virtual  image  of  the  test  letters  at  the  focus  of  the 
convex  lens;  but  this  image  lies  already  at  an  infinite  distance 
behind  the  convex  lens,  and  accordingly,  as  regards  the  size  of  the- 
retinal  image,  the  withdrawal  of  the  eye  a  few  inches  from  the. 
lens  has  no  effect.  If  we  jirefer  to  assume,  with  Mauthner,*  a; 
common  optical  centre  for  the  eye  and  the  convex  lens,  it  is  of 
course  true  that  this  point  recedes  from  the  retina  the  more  the. 
distance  between  the  eye  and  the  convex  lens  is  increased  ;  but  ut 
the  same  time  the  distance  between  this  point  and  the  test  type 
behind  the  lens  increases  in  the  same  proportion,  so  that  the  size- 
of  the  retinal  image  is  unatlected.  That  this  last  must  be  thc- 
case  we  have  already  proved  by  Fig.  25. 

We  have  hitherto  spoken  only  of  the  size  of  the  retinal  image.. 
Generally  the  process  has  been  another  one,  and  the  attempt  has 
been  to  determine  not  the  visual  angle,  but  the  enlargement,, 
assuming  a  so-called  "distance  of  distinct  vision,"  of  8  inches.. 
From  the  present  stand-point  of  ophthalmology  it  seems  very  de- 
sirable to  dispense  altogether  with  such  an  antiquated  idea  as  that 

*  L.  c,  pag.  179.. 


108  SIZE   OF   THE    OPHTHALMOSCOPIC   IMAGE. 

of  "a  distance  of  distinct  vision."  There  is  no  more  reason  for 
assuming  it  to  be  8  inches  than  80  or  800  inches.  We  measure 
the  magnifying  power  of  a  telescope,  for  instance,  by  superposing 
the  enlarged  image  of  a  distant  scale,  as  seen  by  the  one  eye 
through  the  instrument,  upon  the  image  of  the  same  scale  as  seen 
by  the  other  and  naked  eye.  We  compare,  in  fact,  the  size  of 
the  retinal  images,  or,  what  is  the  same  thing,  we  ascertain  by 
how  much  the  visual  angle  for  the  scale  in  question  is  increased 
by  the  telescope.  Surely  no  one  will  assert  that  the  moon  viewed 
through  an  opera-glass  which  magnifies  two  or  three  times  ap- 
pears two  or  three  times  larger  than  tiiis  celestial  body  would, 
could  we  observe  it  at  the  distance  of  8  inches,  the  so-called  dis- 
tance of  distinct  vision.  Now,  .whether  we  observe  a  distant 
object  through  a  Galilean  telescope,  or  a  near  object  through  a 
Briicke  lens,  or  the  fundus  of  a  myopic  eye  in  the  upright  image, 
with  the  help  of  a  concave  glass,  each  case  is  governed  by  exactly 
the  same  optical  law^s,  and  it  is  impossible  to  measure  processes 
which  are  the  same  by  standards  which  are  different. 

Moreover,  it  is  plain  that  calculations  of  the  ophthalmoscopic 
enlargement,  based  upon  an  assumed  distancie  of  distinct  vision 
of  8  inches,  furnish  inaccurate  results.  To  me  at  least,  the  optic 
disc  in  the  upright  image  appears  about  as  large  as  E.  v.  Jaeger 
has  delineated  it  in  his  ophthalmoscopic  hand  atlas.  The  most  of 
these  figures,  as  the  author  expressly  states,  and  as  one  may  sat- 
isfy himself  by  measurement,  are  draw'n  as  if  magnified  7-fold ; 
how  does  that  agree  with  the  15-  to  24-fold  enlargement  which 
has  been  calculated  for  the  upright  image?  It  of  course  is 
undoubtedly  true  that  a  virtual  image  included  in  a  visual  angle 
of  5.73°,  projected  at  a  distance  of  200  mm.  (about  8  inches), 
would  have  a  length  of  20  mm.;  but  to  me  at  least  the  optic  disc 
never  appears  so  large.  This  question,  moreover,  is  of  no  practi- 
cal importance,  since  we  possess  no  means  of  measuring  the  size 
of  the  image,  but  are  simply  left  dependent  upon  a  method  of 
estimation  full  of  sources  of  error.  The  case  is  exactly  tiie  same 
as  in  magnifying  with  a  lens.  If  we  are  not  contented  with  reck- 
oning the  size  of  the  visual  angle,  but  insist  on  knowing  the 
degree  of  the  so-called  enlargement,  we  can  proceed  only  in  the 
method  above  described  for  measuring  the  telescopic  enlargement. 
We  designate  the  visual  angle  under  which  we  see  the  object  with 


SIZE    OF   THE   OPHTHALMOSCOPIC    IMAGE.  109 

the  naked  eye  by  the  letter  d,  and  the  angle  under  which  it  appears 
at  the  same  distance,  but  with  the  help  of  the  magnifying  instru- 
ment, by  the  letter  Z);  then  evidently  the  enlargement  is  expressed 
by  the  relation  of  d  to  D.  But  in  magnifying  with  a  lens,  the  rela- 
tion of  c?  to  D  depends  essentially  upon  the  distance  between  the  eye 
and  the  object  observed  through  the  lens.  If  the  object  be  at  the 
focus  of  the  lens  we  cannot  estimate  the  size  of  the  imasre,  since  it 
lies  at  an  infinite  distance  and  is  therefore  infinitely  large ;  but  the 
visual  angle  under  which,  in  this  case,  the  object  appears,  is  simply 
dependent  upon  the  focal  length  of  the  lens.  We  designate  the 
size  of  the  object  by  a,  and  its  distance  from  the  convex  lens  by  c, 
then  will  the  visual  angle  -D== -,  no  matter  how  great  the  distance 
of  the  lens  from  our  eye.  The  visual  angle  of  the  same  object 
observed  from  the  same  distance  with  the  naked  eye  would  be  c?=?, 
where  a  again  represents  the  size  of  the  object,  and  k  its  distance 
from  the  optical  centre  of  our  eye.  The  quotient  -  becomes  of 
course  smaller  the  more  the  lens,  with  the  object  always  at  its 
focus,  approaches  the  eye,  and  it  becomes  =1  when  k  and  c  co- 
incide, since,  seen  from  the  middle  of  the  convex  lens,  the  object 
and  image  always  appear  under  the  same  visual  angle.  In  this 
case  it  is  simply  the  very  near  approach  made  possible  by  the 
lens,  which  causes  the  increase  of  the  visual  angle,  and  the  retinal 
image  cast  by  it  would  be  no  larger  than  without  the  lens,  provided 
we  could  accommodate  upon  so  short  a  distance.  Since,  however, 
k  and  c  never  actually  coincide,  the  retinal  image  cast  by  the  lens 
will  always  be  somewhat  larger  than  can  be  obtained  from  the 
same  object  at  the  same  distance,  by  accommodation  alone. 

If  the  object  lie  not  at  the  focus,  but  somewhat  nearer  the  con- 
vex lens,  the  size  of  the  virtual  image  may  be  easily  calculated 
from  the  well-known  optical  formula.  In  order  to  see  the  image 
distinctly,  the  observer's  eye  must  either  be  myopic,  so  that  its 
far  point  coincides  with  the  place  of  the  image,  or  it  must  make 
an  effort  of  accommodation,  to  adjust  it  upon  the  place  of  the 
image.  The  visual  angle,  however,  under  which  the  object  appears, 
is  not  necessarily  smaller  than  it  would  be  if  the  object  were  at 
the  focus  of  the  convex  lens :  it  may  even  be  larger.  If  we  place 
in  front  of  our  eye  a  convex  lens  with  a  focal  distance  of  10  inches, . 
and  if  we  now  place  a  small  object  in  the  focus  of  the  lens,  it  wilL 


110  SIZE   OF   THE   OPHTHALMOSCOPIC   IMAGE. 

evidently  appear  under  a  considerably  smaller  visual  angle  than 
when  we  bring  the  object  so  near  that  its  virtual  image  coincides 
with  our  near  point. 

•  If  the  object  lie  beyond  the  focus  of  the  convex  lens,  the  case 
is  the  same  as  that  when  we  make  the  ophthalmoscopic  examina- 
tion in  the  inverted  image.  The  size  of  the  inverted  real  image 
is  easily  calculated,  since,  from  the  optical  centre  of  the  convex 
lens,  both  object  and  image  are  included  in  the  same  angle.  Their 
sizes  are  proportional  to  their  respective  distances  from  the  convex 
lens.  The  calculation  is  only  slightly  more  complicated  when,  as 
in  the  case  of  the  ophthalmoscopic  examination  in  the  inverted 
image,  the  image  is  not  cast  directly  from  the  eye,  but  with  the 
help  of  a  convex  lens.  Wiien  using  a  convex  lens  of  80  mm. 
(3  inches)  focal  distance,  and  held  at  that  distance  from  the  eye, 
the  relation  of  the  size  of  the  optic  disc  to  its  inverted  image  is 
found,  upon  calculation,  to  be  as  follows : 

1.  In  emmetropia,  as  1  :  5.3. 

2.  In  M^^  (more  exactly  Mj-g^  mm.),  as  1  :  4.6. 

3.  In  apparent  myopia  3^, — that  is,  when  the  accommodation  of 
the  emmetropic  eye  under  examination  is  adjusted  for  that  distance, 
—as  1  :  5.2. 

4.  In  H^  (^y^q74  mm.),  as  1  :  6.1. 

5.  In  the  same  grade  of  latent  hypermetropia,  as  1  :  5.9. 
These  relations,  however,  are  true  only  for  the  case  in  which  the 

convex  lens  is  held  at  its  focal  distance  from  the  examined  eye. 
In  emmetropia,  to  be  sure,  the  distance  of  the  lens  from  the  eye 
has  no  influence  uj>on  the  size  of  the  image,  since  the  rays  pro- 
ceeding from  tlie  fundus  always  fall  parallel  upon  the  lens,  and 
will  consequently  always  intersect  at  its  focus.  But  in  hyper- 
metropia the  size  of  the  image  increases  with  the  distance  of  the 
convex  lens  from  the  eye.  The  far  point  of  the  hypermetropic 
eye  and  the  place  of  the  inverted  image  are  conjugate  foci.  The 
nearer  the  convex  lens  is  brought  to  the  examined  eye  the  larger 
the  image,  and,  inversely,  the  more  it  is  withdrawn  the  smaller 
the  image.  For  the  same  reasons,  the  size  of  the  image  increases 
in  myopia  with  the  distance  of  the  lens  from  the  eye.  But  the 
inverted  image  is  always  greater  in  hypermetropia  and  less  in 
myopia  than  it  is  in  emmetropia. 

If  an  extreme  case  of  myopia,  say  M-2^,  be  examined  with  a 


THE   OPHTHALMOSCOPE.  Ill 

convex  lens  which  is  not  too  strong,  say  +  ^,  the  inverted  image  of 
the  fundus,  cast  from  the  eye  itself,  may  lie  between  the  examined 
eye  and  the  convex  lens.  The  inverted  image,  cast  from  the 
myopic  eye,  wall  be  enlarged  very  little  by  the  convex  lens,  be- 
cause it  lies  too  near  it,  but  a  great  advantage  is  gained  for  the 
field  of  vision.  When  the  glass  is  correctly  held  (compare  page 
96),  the  iris  disappears  out  of  the  field  of  vision,  and  the  field 
itself  becomes  considerably  larger  than  it  appears  without  the 
convex  lens. 

Hitherto  we  have  supposed  the  fundus  of  the  eye  to  be  illumi- 
nated, and  we  must,  therefore,  now  describe  the  means  by  which 
it  is  possible  to  throw  a  beam  of  light  in  the  direction  of  our  line 
of  vision,  into  the  eye  under  examination.  This  is  done  by  means 
of  a  transparent  or  perforated  mirror.  The  ophthalmoscope,  as 
originally  constructed  by  Helmholtz,*  has,  as  reflectors,  three 
plates  of  glass  with  parallel  plane  surfaces,  placed  one  over  the 
other.  In  order  to  increase  as  much  as  possible  the  intensity 
of  the  reflected  light,  they  are  placed  at  an  angle  of  36°  with  the 
optical  axis  of  the  instrument.  Perforated  mirrors,  however, 
soon  came  to  be  preferred,  on  account  of  the  better  illumination 
which  they  give.  Rutef  introduced  the  use  of  the  concave  mirror. 
CocciusJ  preferred  to  produce  the  same  effect  by  the  combination 
of  a  plane  mirror  with  a  convex  illuminating  lens. 

It  is  desirable  in  practice  to  be  able  to  vary  the  intensity  of  the 
light,  especially  in  the  examination  in  the  upright  image.  In 
this  respect  the  mirror  of  Coccius  possesses  an  advantage  over  the 
concave  mirror,  for  one  can  use  the  plane  mirror  either  alone 
or  in  combination  with  the  convex  illuminating  lens.  Jaeger's 
ophthalmoscope  is  so  contrived  that  either  a  concave  or  a  plane 
mirror,  or  Helmholtz's  reflecting  glass  plates,  can  be  set  in  it  at 
pleasure.  Another  advantage  possessed  by  this  instrument  is, 
that  the  correcting  lenses,  which  are  placed  as  oculars  behind 
the  mirror,  can  always  be  held  perpendicular  to  the  observer's 
line  of  vision, — an  important  point  in  cases  in  which  somewhat 
strong  lenses  are  used. 

Giraud-Teulon's  binocular  ophthalmoscope  deserves  a  particular 

*  Beschreibung  elnes  Augenspiegels,  1851. 

f  Der  Augenspiegel  und  das  Optometer,  1852. 

J  Ueber  die  Anwendung  des  Augenspiegels,  etc.,  1853. 


112 


THE    BINOCULAR   OPHTHALMOSCOPE. 


mention.  Its  principle  may  be  thus  explained.  Behind  the  open- 
ing in  the  concave  mirror,  Fig.  27,  are  two  rhomboidal  glass  prisms, 
whose  end  surfaces  stand  at  an  an^le  of  45°  with  the  longitudinal 
axes  of  the  prisms.  The  rays  a  r  and  a  I  proceeding  from  the 
point  a  are  reflected  on  the  surfaces  r  and  I  towards  r'  and  I',  where 
they  experience  another  reflection  in  the  direction  r'  a'  and  I'  a', 

Fig.  27. 


parallel  to  r  a  and  I  a.  If  instead  of  the  point  a  we  have  a  solid 
object,  its  retinal  images  Avill  be  so  related  as  if  the  object  were 
seen  under  a  very  slight  angle  of  convergence,  equal  to  the  angle  lar. 

As  seen  in  Fig.  27,  the  lines  of  vision  intersect  each  other  in  a 
point  much  farther  from  the  eye  than  tlie  point  a,  upon  which  the 
accommodation  must  be  adjusted.  This  difficulty  can  be  over- 
come either  by  adjusting  the  accommodation  by  convex  glasses 
upon  tlie  point  a  without  making  any  greater  demand  on  the  ac- 
commodation than  is  natural  Avith  a  slight  angle  of  convergence; 
or  by  means  of  prisms  with  their  refracting  angles  turned  inward, 
a  convergence  of  the  visual  axes  may  be  induced,  more  nearly  cor- 
responding to  the  distance  of  the  point  a;  or,  finally,  both  methods 
may  be  combined  by  the  use  of  convex  prismatic  glasses  with  the 
refracting  angle  turned  inward. 

If  the  perception  of  the  third  dimension  depend  upon  the  fact 
that  the  retinal  images  in  the  two  eyes  are  not  identical,  but  show 
certain  perspective  diffiirences,  these  differences  can  be  but  very 
small  when,  as  is  the  case  in  the  binocular  ophthalmoscope,  the 
lines  of  vision  include  so  acute  an  angle.  Hering's  experiment 
gives,  therefore,  by  means  of  this  instrument,  only  a  very  uncer- 
tain perception  of  the  third  dimension.     When  practising  it,  one 


hering's  experimekt.  113 

is  mistaken  just  about  as  often  as  in  monocular  vision.  We  shall 
have  repeated  occasion  to  mention  this  experiment ;  it  is  the  only 
one  which  in  a  simple  way  shows  whether  there  is  a  normal  bin- 
ocular act  of  vision.     It  is  conducted  in  the  following  manner: 

A  cylindrical  tube  about  25  centimetres  in  length,  and  wide 
enough  to  be  looked  through  with  both  eyes,  has  at  one  end,  and 
fastened  on  its  outside,  two  long  needles,  which  must  be  so  bent 
outward  that  they  cannot  be  seen  on  looking  through  the  tube. 
A  fine  silken  thread  connects  the  point  of  one  needle  with  that  of 
the  other.  Midway  between  the  needles  is  a  knot  in  the  thread, 
or,  better  still,  a  small  bead,  which  then  lies  in  the  centre  of  the 
field  of  vision,  when  one  looks  through  the  tube.*  The  tube  is 
held  close  before  the  face,  with  the  thread  horizontal,  and  so  that 
both  eyes  look  through  the  tube ;  the  bead  in  the  middle  of  the 
field  of  vision  serves  as  a  fixation-point.  Small  balls,  of  different 
sizes,  are  allowed  to  fall  about  twelve  times,  one  after  the  other, 
some  before  and  some  behind  the  bead.  One  who  sees  binocularly 
can  tell  with  certainty  whether  a  ball  falls  within  or  beyond  the 
fixation-point,  while  one  who  perceives  the  retinal  image  of  one 
eye  only,  is  frequently  deceived  ;  he  can,  when  the  experiment  is 
carefully  conducted,  only  guess  the  place  of  the  ball,  and  therefore 
is  mistaken  in  half  the  cases. 

It  is  the  same  when  one  makes  this  experiment  with  the  bin- 
ocular ophthalmoscope.  Such  binocular  vision  as  is  made  possible 
by  that  instrument  is,  for  the  reasons  just  given,  insufficient  to 
give  a  proper  perception  of  the  third  dimension. 

Although  there  is  a  wide-spread  prejudice  in  favor  of  the  bin- 
ocular ophthalmoscope,  we  should  remember  that  in  monocular 
vision,  also,  we  have  a  means  at  our  disposal  by  which  to  judge  of 
the  third  dimension,  and,  further,  that  absolutely  identical  retinal 
images  may  produce  a  stereoscopic  effect.  One  receives,  for  in- 
stance, an  undeniable  impression  of  solidity  when  one  unites, 
stereoscopically,  two  photographs  taken  from  one  and  the  same 
negative.  In  such  a  case  there  is,  of  course,  simply  an  optical 
illusion,  to  be  explained  by  the  fact  that  the  visual  impression 
of  solidity  does  not  depend  exclusively  upon  certain  differences 

*  The  description  here  given  varies  somewhat  from  the  original  of  Hering: 
it  is,  however,  more  convenient.  Conip.  Hering,  Arch,  fiir  Ophth.,  B.  xiv. 
1,  pag.  3. 


114  THE    BINOCULAE   OPHTHALMOSCOPE. 

between  the  retinal  images  in  the  two  eyes,  but  it  is  caused  by 
the  perspective,  the  illumination,  etc.,  even  with  identical  retinal 
images,  or  in  monocular  vision.  Whoever  wishes  to  repeat  the 
simple  experiment  of  uniting,  stereoscopically,  two  identical  pho- 
tographs, can  satisfy  himself  that  such  an  optical  illusion  of  neces- 
sity occurs.  The  same  principle  is  employed  in  Coccius'  binocular 
mirror.  Behind  a  perforated  concave  mirror  is  placed  a  plane 
mirror,  also  perforated,  with  its  reflecting  surface  directed  for- 
ward toward  the  eye  to  be  examined,  and  forming  with  the  line 
of  vision  of  the  examiner  an  angle  of  about  45°.  Suppose  these 
two  perforated  mirrors  to  be  held  in  front  of  the  left  eye  of  the 
examiner,  and  that  before  the  right  eye  be  held  an  imperforate 
plane  mirror  with  its  reflecting  surface  turned  toward  the  others. 
The  ophthalmoscopic  image  is  reflected  from  the  first  plane  mirror 
to  the  second,  and  from  that  to  the  right  eye  of  the  examiner. 
He  receives,  therefore,  from  the  ophthalmoscopic  object,  it  is  true, 
two  retinal  images,  but  they  are  alike  in  the  strictest  mathematical 
sense.  One  of  these  images  is  always  somewhat  smaller  than  the 
other,  and  in  this  case  it  is  that  in  the  right  eye,  because  that  eye 
is  farther  from  the  object  than  the  left.  The  difference  of  the  two 
retinal  images,  upon  which  the  perception  of  depth  depends,  in  so 
far  as  it  involves  a  relation  of  correspondence  of  the  retinae,  is 
here  wanting  entirely. 

In  spite,  however,  of  the  negative  result  of  Hering's  experi- 
ment, we  do,  with  the  aid  of  the  binocular  instrument,  form  a 
better  judgment  of  the  third  dimension  in  the  fundus  of  the  eye. 
This  is  due  to  the  fact  that  in  using  this  instrument  we  have  the 
convergence  of  the  visual  axes  to  assist  in  forming  a  judgment  of 
the  third  dimension.  The  same  is  true  of  the  convergence  of  the 
visual  axes  as  of  the  retinal  images.  If  the  images  be  identical, 
the  convergence  of  the  visual  axes  will  remain  the  same  while 
scrutinizing  them.  But  with  Giraud-Teulon's  binocular  mirror, 
at  least,  the  retinal  images  are  not  absolutely  identical,  and  even 
if  their  differences  be  too  slight  to  be  proved  by  Hering's  experi- 
ment, the  change  in  the  convergence  of  the  visual  axes  is,  perhaps, 
a  more  delicate  means  of  judging  of  distances.  Finally,  the 
binocular  mirror  makes  it  possible  to  observe  the  image  for  a 
considerable  time. 

For  many  cases  it  is  simplest  and  most  advantageous,  in  making 


OPHTHALMOSCOPIC   ILLUMINATION.  115 

a  binocular  examination,  to  employ  two  concave  mirrors ;  these 
are  placed  in  a  frame  provided  with  a  handle,  and  are  separated 
from  each  other  by  a  distance  corresjDonding  to  the  distance  be- 
tween the  two  eyes ;  each  mirror  revolves  about  both  a  vertical 
and  a  horizontal  axis.  It  is  only  necessary,  then,  to  so  arrange 
the  mirroi*s  that  the  two  images  of  the  light  cast  by  them  fall 
upon  each  other,  in  order  to  be  able  to  see  ophthalmoscopically 
with  both  eyes.  Cloudiness  of  the  lens  or  vitreous,  and  many 
cases  of  detachment  of  the  retina,  may  be  observed  binocularly 
ih  this  manner  under  the  most  favorable  circumstances.  This 
method  is  not  available  for  objects  lying  deeper  in  the  eye,  nor 
for  examination  in  the  inverted  image. 

The  source  of  light  for  the  ophthalmoscopic  examination  may 
be  either  a  bright  oil-  or  gas-flame,  or  daylight.  The  last,  as  has 
been  shown  by  Helmholtz,*  is  the  best  light  for  all  cases  where  it 
is  desirable  to  judge  of  the  true  color  of  the  fundus,  or  to  detect 
slight  cloudiness  in  the  retina.  Moreover,  it  has  the  advantage 
of  dazzling  the  patient  less  than  lamp-light. 

Since,  in  general,  daylight  is  preferred  to  artificial  illumination 
in  cases  where  it  is  wished  to  recognize  fine  shades  of  color,  it  of 
course  suggested  itself  to  make  use  of  this  advantage  in  ophthal- 
moscopic examination.  It  is  noticed  that  by  daylight  the  ophthal- 
moscopic image  has  a  yellow  shade,  which  disappears  entirely  by 
artificial  illumination.  Under  normal  relations,  this  effect  is  seen 
most  distinctly  upon  the  optic  nerve. 

The  more  exact  recognition  of  shades  of  color  and  differences 
in  illumination  possible  by  daylight,  is  probably  the  reason  why 
slight  cloudiness,  especially  in  the  retinal  substance,  which  cannot 
be  seen  by  artificial  illumination,  becomes  visible  by  daylight. 
Eyes  absolutely  physiological  often  furnish  proof  of  this  fact. 

The  illumination  by  daylight  is  best  arranged  by  allowing  it 
to  enter  a  dark  room  through  an  opening  3  or  4  centimetres  in 
diameter,  cut  in  the  window-shutter.  The  ophthalmoscope  may 
then  be  directed  toward  the  sky  just  as  is  the  mirror  of  the 
microscope.  Direct  sunlight  ought,  of  course,  not  to  be  used 
except  in  eyes  absolutely  blind. 

The  use  of  daylight  is  particularly  applicable  to  examinations 

*  Besclireibiing  eines  Augenspiegels,  Berlin,  1851,  pag.  19. 


116  OPHTHALMOSCOPIC   DIAGNOSIS  OF   REFRACTION. 

of  the  optic  nerve  and  retina ;  for  all  other  cases  a  good  lamp- 
flame  is  all-sufficient,  and  in  many  cases  more  convenient. 

OPHTHALMOSCOPIC   DIAGNOSIS   OF  THE  CONDITION  OF    REFRAC- 
TION. 

The  use  of  the  ophthalmoscope  for  the  diagnosis  of  the  con- 
dition of  refraction  is  as  old  as  the  use  of  this  instrument  in  gen- 
eral. Helmholtz*  mentions  a  case  in  which,  in  a  perfectly  blind 
eye,  by  the  help  of  the  ophthalmoscope,  he  could  decide  the 
important  question  whether  certain  former  difficulties  of  vision; 
which  the  patient  complained  of,  depended  upon  myopia  or  incip- 
ient amblyopia.  He  pointed  out  as  an  advantage  of  this  method 
that  it  makes  the  examiner  entirely  independent  of  the  statements 
of  the  patient,  since  he  himself  sees  with  the  patient's  eye,  at 
least  with  the  refracting  part  of  it.  Cases  in  which  it  is  desirable 
to  be  entirely  independent  of  the  statements  of  the  patient  are, 
in  fact,  frequent.  Indeed,  it  happens  often  that  the  ophthalmo- 
scopic examination  first  gives  a  proper  direction  to  the  functional 
examination. 

AVe  have  already  explained  the  manner  in  which  the  condi- 
tion of  refraction  is  disclosed  by  the  ophthalmoscopic  examina- 
tion. The  degree  of  the  anomaly  may  be  determined  by  the  same 
method.  Above  all  things  the  observer  must  be  certain  that  both 
he  and  the  patient  have  fully  relaxed  their  accommodation.  He 
can  then,  observing  the  distance  from  the  eye  under  examination^ 
determine  the  degree  of  the  refraction  from  the  number  of  the 
lens  with  which  the  fundus  can  be  distinctly  seen  in  the  upright 
image.  If  one  wish  to  determine  exactly  the  condition  of  re- 
fraction by  the  ophthalmoscopic  examination,  it  is  best  to  paralyze 
the  accommodation  by  atropine,  and  to  use  as  a  test-object,  not 
the  optic  disc,  but  one  of  the  fine  retinal  vessels  running  from  it 
toward  the  macula  lutea.  In  such  a  case  it  is  well,  as  Cocciusf 
has  proposed,  to  place  the  correcting  lens  close  in  front  of  the  eye 
under  examination,  between  it  and  the  mirror,  and  to  avoid  the 
annoying  reflex  by  slight  movements  of  the  lens.  The  correcting 
lens  is  then  at  the  same  distance  from  the  eye  as  it  would  be  if 
used  as  a  spectacle-glass, 

*  Beschreibung  eines  Augenspiegels,  pag.  38. 

f  Ueber  die  Anwendung  des  Augenspiegels,  Leipzig,  1853,  pag;  28. 


OPHTHALMOSCOPIC   DIAGNOSIS   OF   EEFRACTION.  117 

The  ophthalmoscopic  diagnosis  of  the  condition  of  refraction 
furnishes  an  excellent  check  upon  the  results  derived  from  the 
examination  with  test  letters;  especially  is  this  true  in  all  those 
cases  in  which  an  anomaly  of  refraction  is  complicated  by  ambly- 
opia. In  myopia,  under  these  circumstances,  there  are  generally 
other  changes  in  the  fundus  which  immediately  attract  attention. 
Hypermetropia  and  astigmatism,  on  the  contrary,  often  exist  in 
connection  with  a  form  of  amblyopia  in  which  there  are  no  mate- 
rial changes  in  the  fundus,  while  the  poorness  of  vision  makes  it 
difficult  or  impossible  to  determine  the  condition  of  refraction  by 
testing  the  power  of  vision.  These  cases  would  be  enigmatical  if 
we  had  not  the  ophthalmoscope  to  aid  us. 

The  ophthalmoscopic  diagnosis  of  meridional  asymmetry  de- 
pends upon  the  optical  nature  of  this  anomaly.  AVe  have  above 
explained  that  we  see  the  fundus  of  the  eye  in  the  upright  image 
as  if  through  a  lens.  Under  these  circumstances,  the  shorter  the 
focal  distance  the  greater  the  enlargement, — that  is,  it  is  greatest 
in  the  direction  of  the  meridian  which  possesses  the  highest  re- 
fraction, generally  in  the  vertical.  The  image  of  a  round  object, 
for  instance  of  the  optic  disc,  will  not  appear  round,  but  oval  and 
elongated,  in  the  direction  of  the  meridian  of  shortest  focal  dis- 
tance,— that  is,  generally  in  the  vertical  direction.  The  appear- 
ance is  exactly  reversed  in  the  examination  in  the  inverted  image. 
In  the  meridian  of  shortest  focal  distance  the  image  lies  nearer 
the  convex  glass  than  in  the  other  principal  meridians:  it  is  there- 
fore less  enlarged  than  in  the  meridian  of  longest  focal  distance. 
A  round  optic  disc  appears,  therefore,  not  round,  but  elongated, 
in  the  direction  of  the  meridian  of  longest  focal  distance. 

We  ought  not  to  forget  that  in  the  0{)hthalmoscopic  examina- 
tion we  do  not  see  the  fundus  as  if  with  the  naked  eye,  but  always 
only  an  optical  image  of  the  fundus,  an  image  depending  upon 
the  nature  of  the  apparatus  producing  it.  If  now  in  the  upright 
image  the  optic  disc  appear  oval  in  the  vertical  direction,  and  in 
the  inverted  image  oval  in  the  horizontal  direction,  it  is  plain 
that  it  can  anatomically  l)e  neither  the  one  nor  the  other,  but  that 
this  change  of  form  in  the  ophthalmoscopic  image  rests  upon 
optical  grounds.  Frequently  the  optic  disc  is  actually  oval,  and 
oftener  elongated  in  the  vertical  than  in  the  horizontal  direction, 
as  may  be  ascertained  by  the  comparative  examinations  in  the  up- 


118  OPHTHALMOSCOPIC   DIAGNOSIS   OF  ASTIGMATISM. 

right  and  inverted  images.  This,  however,  does  not  hinder  in 
the  least  the  ophthahiioscopic  diagnosis  of  astigmatism,  since 
neither  the  examination  in  the  upright  nor  in  the  inverted  image 
is  by  itself  sufficient,  but  the  diagnosis  is  always  based  upon  a 
comparison  of  the  two  images.  The  change  of  form  in  both  the 
upright  and  inverted  image,  caused  by  astigmatism,  is  always 
present,  be  the  anatomical  form  of  the  optic  disc  what  it  may.  A 
vertically  elongated  disc  would  then  in  the  upright  image  appear 
much  more  elongated  in  the  vertical  direction ;  in  the  inverted 
image,  it  would  appear  nearly  round.  A  horizontally  elongated 
disc  would,  on  the  contrary,  appear  nearly  round  in  the  upright 
image,  and  in  the  inverted  image  still  more  horizontally  elongated. 
To  compare  more  easily  the  two  images,  it  is  important  that  they 
should  be  as  nearly  as  possible  the  same  size.  This  condition  is 
sufficiently  fulfilled  if  one  use  a  convex  lens  of  3  inches  focal 
length  when  examining  in  the  inverted  image.  It  is  still  more 
important  that  the  convex  glass  be  not  held  obliquely,  so  as  to 
cause  asymmetry  and  change  of  form  in  the  inverted  image. 
Care  must  also  be  taken  that  the  convex  glass  be  so  centred  that 
the  images  of  the  flame  reflected  from  its  anterior  and  posterior 
surfaces  cover  each  other,  and,  when  possible,  are  nearly  in  line 
with  the  optic  disc.    • 

Finally,  it  is  to  be  mentioned  that  when  examining  astigmatic 
eyes  in  the  inverted  image  the  apparent  form  of  the  optic  disc  is 
also  dependent  upon  the  distance  of  the  convex  gla&s.  If,  for 
instance,  there  be  emmetropia  in  the  vertical  meridian,  and  hyper- 
metropia  in  the  horizontal  meridian,  then,  as  before  said,  an  ana- 
tomically round  optic  disc  would  appear  horizontally  elongated. 
Since,  however,  in  hypermetropia  (comp.  page  110)  the  size  of 
the  image  increases  as  the  convex  lens  approaches  the  eye,  the 
difference  between  the  horizontal  and  vertical  extent  of  the  image 
will  be  the  more  striking  the  less  the  distance  between  the  convex 
lens  and  the  eye.  The  case  is  reversed  when  there  is  emmetropia 
in  the  horizontal  meridian  and  myopia  in  the  vertical.  In 
myopia  the  size  of  the  inverted  image  increases  with  the  distance 
of  the  convex  lens  from  the  eye.  The  preponderating  enlarge- 
ment in  the  horizontal  meridian  is  least  when  the  lens  is  nearest 
the  eye,  and  becomes  more  distinct  the  farther  the  lens  is  with- 
drawn. 


THE   OPHTHALMOME'BEE.  119 

In  astigmatism  the  optic  disc  often  appears  irregularly  and 
incompletely  surrounded  by  a  bright  space,  which  anatomically 
is  the  sclera  shining  through  the  choroid.  Under  these  circum- 
stances one  must  be  careful  to  observe  the  proper  boundary  of  the 
nerve  itself.  If,  however,  the  nerve  and  the  scleral  stripe  sur- 
rounding it  present  a  regularly  bounded  and  nearly  round  figure, 
it  may  be  more  advantageous  to  direct  the  attention  upon  this 
distinctly  bounded  surface. 

Coccius*  proposes  for  the  diagnosis  of  astigmatism  the  following 
method  of  examination.  From  the  distance  of  from  20  to  24 
inches  the  image  of  a  broad  bright  flame  is  cast  by  a  plane  steel 
mirror  into  the  fundus  of  the  eye ;  a  small  rod,  for  instance  a  lead- 
pencil,  is  now  to  be  held  immediately  before  the  flame,  and  the 
observer  is  to  notice  whether  the  image  of  this  rod,  when  held  in 
all  positions,  vertical,  horizontal,  or  inclined,  appears  of  uniform 
distinctness  and  size.  If  such  be  the  case,  the  rays  are  focused 
homocentrically.  If,  on  the  contrary,  the  rod  when  held  verti- 
cally appears  in  the  fundus  undefined,  dull,  and  broad,  but  when 
held  horizontally  appears  sharp,  black,  and  narrow,  then  will  this 
phenomenon  agree  always  with  the  subjective  observation, — that 
is,  the  astigmatic  sees  vertical  lines  indistinctly,  but  horizontal 
ones  distinctly. 

THE    OPHTHALMOMETEK. 

The  ophthalmometer  was  constructed  by  Helmholtz  for  the 
purpose  of  measuring  exactly  the  curved  surfaces  participating  in 
accommodation. 

The  images  cast  from  a  convex  reflecting  surface  are  so  much 
the  smaller  the  shorter  the  radius  of  curvature.  Consequently  we 
may  use  the  size  of  an  image  to  reckon  the  radius  of  curvature. 
The  great  difficulty,  however,  in  measuring  the  images  reflected 
from  the  cornea  is,  that  it  is  impossible  to  hold  the  living  eye  im- 
movable. The  images  from  a  spherical  reflecting  surface  or  from 
the  cornea  can  be  distinct  only  when  all  the  rays  from  the  object 
fall  nearly  perpendicularly  upon  the  reflecting  surface.  It  follows 
that  for  the  purpose  of  this  measurement  only  such  images  can  be 
used  as  are  considerably  shorter  than  the  radius  of  curvature;  they 
should  not  exceed  one-fourth  its  length.     Even  then,  an  error  in 


*  Ueber  den  Mechanismus  der  Accommodation,  pag.  142. 


120  THE    OPHTHALMOMETEE. 

the  measurement  of  the  image  is  multiplied  by  4  in  calculating  the 
radius  of  the  cornea.  The  size  of  the  image  must  therefore  be 
determined  to  within  the  hundredth  part  of  a  millimetre,  in 
order  to  calculate  the  radius  of  the  cornea  within  a  hundredth 
part  of  its  length,  that  length  being  on  an  average  about  8  milli- 
metres. 

Of  course  there  is  no  means  of  fastening  the  head  in  such  a 
way  as  to  prev^ent  movements  of  y^-q  of  a  millimetre.  It  is  im- 
possible by  applying  a  graduated  scale  directly  to  the  cornea  to 
make  any  measurements  of  the  necessary  exactitude.  The  prob- 
lem, then,  was  to  measure  the  movable  corneal  image  while  in 
motion.  Helmholtz*  solved  this  problem  by  the  construction  of 
his  ophthalmometer.  This  instrument  depends  upon  the  principle 
that  objects  seen  through  glass  plates  with  plane  parallel  surfaces, 
placed  at  an  angle  with  the  line  of  vision,  seem  displaced,  and 
that  this  displacement  is  greater  the  greater  the  angle  of  incidence 
of  the  rays  upon  the  plate. 

Fig.  28. 

In  Fig.  28,  let  A  he  a  telescope  before  whose  objective  glass, 
and  inclined  to  its  axis,  are  placed  the  two  glass  j^lates  a^  b^  and 
a^  h^;  the  plate  o}  b^  covers  the  right  half  and  the  plate  a^  P 
the  left  half  of  the  objective.  The  telescope  is  directed  upon 
the  object  c  d;  then  to  the  observer  the  image  seen  through  the 
plate  a^  b^  does  not  appear  to  be  at  c  d,  but  at  c^  d^,  and  that 
seen  through  the  plate  a'  b^  at  c^  d^.  Both  images  appear  simul- 
taneously side  by  side  in  the  field  of  the  telescope.  If  now  the 
glass  plates  be  so  turned  that  the  end  c^  of  the  first  image  corre- 
spond with  the  end  d^  of  the  second  image,  and  if  the  angle  be 
known  through  which  the  plates  have  been  revolved,  then  the 
length  of  c  d  can  be  calculated.  The  adjustment  of  the  edges  of 
the  images  against  each  other  can  be  very  exact,  even  when  the 
field  of  vision  is  in  motion,  since  the  two  images  c^  d^  and  c^  d^ 
always  move  together,  and  their  apposition  is  not  disturbed. 

*  Arch.  f.  Opth.,  Bd.  i.  2,  pag.  1-74. 


THE   OPHTHALMOMETER.  121 

The  instrument  is  so  contrived  that  the  two  glass  plates  always 
revolve  through  the  same  angle,  and  their  revolution  can  be 
observed  on  a  vernier  scale.  In  order  to  calculate  the  size  of  the 
image  it  is  necessary  to  know  the  angle  through  w^hich  the  plates 
revolve,  their  thickness,  and  the  index  of  refraction  of  the  glass 
from  which  they  are  ground.  According  to  Donders,*  it  is  well  to 
determine  experimentally,  for  each  ophthalmometer,  by  what  angu- 
lar position  of  the  glass  plates  known  dimensions  are  measured. 
A  fine  scale,  divided  into  tenths  of  millimetres,  is  observed  through 
the  ophthalmometer,  and  it  is  determined  through  what  angle 
the  plates  must  revolve  to  measure  0.1,  0.2,  0.3  millimetres,  and 
so  forth.  A  tabulated  statement  of  the  results  thus  obtained  en- 
ables one  to  see  at  a  glance  the  size  of  a  corneal  image  as  soon  as 
one  has  read  from  the  instrument  the  angle  through  which  the 
glass  plates  have  been  revolved  in  order  to  bring  the  ophthalmo- 
metric  double  images  in  apposition. 

The  radius  of  curv^ature  of  the  cornea  measured  in  the  line  of 
vision  has,  according  to  Donders,  an  average  length  of  7.7  milli- 
metres. It  appears  that  it  grows  shorter  with  increasing  years. 
At  all  events,  the  former  prevailing  opinion  that  presbyopia 
depends  upon  a  flattening  of  the  cornea  must  be  regarded  as  fully 
disproved. 

So,  too,  contrary  to  the  old  idea  that  myopia  depended  upon 
excessive  curvature  of  the  cornea,  it  has  been  found  that  with  that 
condition  of  refraction  the  radius  of  curvature  is  generally  greater 
than  in  emmetroj^ia ;  in  fact,  that  it  increases  with  the  degree  of 
the  myopia.  The  reason  for  this  is,  that  in  myopia  not  only  the 
visual  axis,  but  all  the  diameters  of  the  eye,  are  increased. 

In  hypermetropia,  also,  Donders  found  the  cornea  on  an  average 
less  curved  than  in  emmetropia ;  still,  he  discovered  no  relation 
between  the  degree  of  the  hypermetropia  and  the  length  of  the 
radius  of  curvature. 

Numerous  measurements  have  proved  that  the  different  me- 
ridians of  the  cornea  possess  radii  of  different  lengths,  and  that 
the  vertical  meridian  generally  has  the  greatest  curvature.  The 
curvature  of  each  individual  meridian  is  nearly  elliptical. 

Under  normal  relations  the  line  of  vision  always  deviates  inward 


*  L.  c,  pag.  17. 


122  THE    OPHTHALMOMETER. 

from  the  centre  of  the  cornea.  The  angle  which  it  forms  with  the 
axis  of  the  cornea  is  called  the  angle  oc.  Donders*  measured 
the  size  of  this  angle  in  the  following  manner.  A  flame  was 
placed  vertically  and  immediately  over  the  ophthalmometer,  and 
its  image  reflected  in  the  cornea  was  observed  ophthalmometrically. 
In  front  of  the  eye  under  examination  was  placed  a  horizontal 
graduated  arc,  with  its  centre  opposite  the  centre  of  rotation  of  the 
eye.     Upon  this  was  placed  a  movable  object,  which  served  as  a 

fixation-point  for  the  eye  under  exam- 
Ficj-  29.  i nation,  and  made  it  possible  so  to  direct 

1'S5>?d^fP^^  it  that  the  image  of  the  flame  should  be 

reflected  exactly  from  the  centre  of  the 
cornea.  This  was  the  case  when,  upon 
revolving  the  glass  plates  of  the  oph- 
thalmometer, the  double  images  of  the 
corneal  reflex  reached  simultaneously 

corl*^'erex""in  order  rl'ee  Ihe  ^^  ^Oth  sidcS  the  bordcr  of  the  double 
eye  under  examination  with  suffi-  images  oftllC  COmCa,  tllCU  half  COVCriug 
cient  exactness  it   must  be  illumi-  1,1  /^  tt        c\r\ 

natedbyaiamp.  cach  Other.     Comp.  Fig.  29. 

The  position  of  the  object  upon  the 
scale  gives  the  angle  which  the  line  of  vision  forms  with  the  axis  of 
the  ophthalmometer,  which  is  directed  upon  the  centre  of  the  cornea. 
The  axis  of  the  ophthalmometer  will  coincide  with  the  axis  of 
the  cornea  provided  the  latter  passes  through  the  centre  of  the  cornea. 
This  provision  is,  however,  fulfilled  ;  for,  according  to  Helmholtz,t 
the  summit  of  the  ellipse  formed  by  the  curvature  of  the  cornea 
coincides  with  the  central  point  of  the  cornea.  This  was  proved 
by  Donders  from  ophthalmometric  measurements  made  for  the 
purpose.  These  results  are  contradicted  by  Woinow,t  according 
to  whose  measurements  the  corneal  axes  do  not  pass  through  the 
middle  of  the  cornea.  According  to  the  same  observer  the  angle 
between  the  visual  line  and  the  corneal  axis  may  vary  greatly  in 
the  two  eyes  of  the  same  individual,  the  distance  of  the  visual  line 
from  the  centre  of  the  cornea  being,  however,  the  same  in  the  two 
eyes.  Woinow  maintained  that  Bonders'  method  did  not  measure 
the  angle  between  the  corneal  axis  and  the  line  of  vision,  but  the 

*  L.  c,  pag.  157. 

t  Arch.  f.  Ophth.,  B.  i.  2,  pag.  23. 

jlbid.,  B.  xvi.  pag.  225. 


THE  OPHTHALMOMETER. 


123 


Fig.  30. 


Fig.  31. 


angle  included  between  the  line  of  vision  and  the  perpendicular 
erected  upon  the  middle  of  the  horizontal  diameter  of  the  base 
of  the  cornea.  Until  this  question  is  decided  it  will  be  well  to 
indicate  the  angle  measured  by  Donders  by  the  letter  oc'. 

The  investigations  conducted  by  Donders  and  Doyer  upon  this 
method  show  that  the  size  of  the  angle  oc'  depends  upon  the  con- 
dition of  refraction.  In  emmetropia  the  angle  a'  averages  5°; 
in  myopia  it  is  smaller,  and  may  indeed  be  negative,  so  that  the 
line  of  vision  deviates  out- 
ward from  the  centre  of  the 
cornea.  In  hypermetropia 
the  angle  oc'  is  greater  than 
in  emmetropia;  in  16  cases 
examined  by  Donders  the 
minimum  of  the  angle  oc' 
was  6°,  the  maximum  9°, 
the  average  7.3°.  In  me- 
ridional asymmetry,  also,  es- 
pecially when  complicated 
with  hypermetropia,  the  de- 
viation of  the  line  of  vision 
from  the  centre  of  the  cornea 
is  generally  greater  than  nor- 
mal. Figs.  30,  31,  and  32 
show  these  relations.*  Fig. 
30  is  an  emmetropic,  Fig.  31 
a  myopic,  and  Fig.  32  a  hy- 
permetropic eye.  In  all  of 
them  the  horizontal  section 
passes  through  the  optic  nerve 
n.  I  is  therefore  the  inner 
(median),  E  the  outer  (tem- 
poral), part  of  the  eye.  The 
axis  of  the  cornea  ^  a  is  not 
directed  upon  the  object  fixed, 
which  casts  its  image  in  the 
fovea  centralis  at  I.     A  straight  line  drawn  from  the  object  fixed 


*From  Donders,  1.  c,  pag.  155, 


124  THE   OPHTHALMOMETER. 

to  its  retinal  image  in  the  fovea  centralis  is  the  line  of  vision  I  V, 
and  we  will  assume  that  this  intersects  the  line  drawn  through  the 
centre  of  the  base  of  the  cornea  and  perpendicular  to  it,  at  the 
optical  centre  of  the  eye.  The  angle  I'  K  a  is  the  angle  between 
that  perpendicular  and  the  line  of  vision  in  the  horizontal  meridian. 
In  the  vertical  it  is  generally  much  smaller,  and  has  no  special 
clinical  interest.  The  point  d  indicates  the  position  of  the  centre 
of  rotation. 

The  most  striking  difference  which  these  figures  present  is  in 
reference  to  the  length  of  the  axes  of  the  eyes.  The  angle  V  K  a 
is  greater  in  the  hypermetropic  eye  than  in  the  emmetropic.  In 
Fig.  31,  representing  a  very  myopic  eye,  it  is  negative.  The  rela- 
tion between  the  condition  of  refraction  and  the  angle  oc'  is  par- 
tially explained  by  the  change  of  form  of  the  eye.  The  direction 
of  the  line  of  vision  is  determined  by  two  points,  the  optical  centre 
J^and  the  macula  lutea.  The  higher  the  degree  of  the  myopia 
the  greater  the  distance  between  ^and  I,  and  this  alone,  if  the 
distance  g  I  remained  constant,  would  diminish  the  deviation  of 
the  line  of  vision  from  the  centre  of  the  cornea.  This  explana- 
tion, however,  is  not  sufficient,  since  the  deviation  may  not  only 
diminish,  but  become  absolutely  negative,  so  that  the  line  of 
vision  deviates  outward  from  the  centre  of  the  cornea.  There  is 
a  more  important  factor  involved,  namely,  an  unsymmetrical  dis- 
tention of  the  eye,  which  is  greatest  upon  the  temporal  side.  The 
optic  disc  on  the  median  side  is  thereby  forced  still  more  inward, 
and  the  same  is  true  of  the  macula  lutea,  although  the  distance 
between  it  and  the  optic  disc  increases,  and  the  choroidal  atrophy 
generally  begins  just  at  this  place.  Since  the  eye  is  relatively 
more  distended  in  its  temporal  than  in  its  median  part,  the  macula 
lutea  becomes  more  and  more  displaced  toward  the  point  in  which 
the  axis  of  the  cornea  pierces  the  posterior  w^all  of  the  eye,  and  the 
physiological  centre  of  tlie  retina  may  even  be  displaced  to  the 
inner  side  of  this  point. 

In  hypermetropic  eyes  the  distance  between  the  optical  centre 
and  the  macula  lutea  is  shorter,  but  if  the  distance  g  I  he  the 
ordinary  normal  one,  the  angle  oc'  must  of  course  be  increased.- 
This  explanation  again  does  not  seem  sufficient,  and  an  abnormal 
displacement  outward  of  the  yellow  spot  must  be  assumed. 

The  varying  deviation  of  the  line  of  vision  from  the  centre  of 


THE   OPHTHALMOMETEE.  125 

the  cornea  is  the  reason  for  the  peculiar  appearance  presented  by 
myopic  and  hypermetropic  eyes.  Our  judgment  respecting  the 
position  of  the  eyes  depends  upon  the  position  of  the  cornea.  In 
emmetropic  eyes,  when  the  lines  of  vision  are  parallel  the  axes 
of  the  cornea  "deviate  outward  by  2x5°  =  10°.  We  regard 
this  as  the  normal  position.  If  now  the  angle  oc'  increase  as  in 
hypermetropia  to  9°,  then  when  the  lines  of  vision  are  parallel 
the  corneal  axes  will  intersect  each  other  behind  the  eye  at  an 
angle  of  2  X  9°  =  18°,  and  this  gives  the  impression  of  diver- 
gence. An  apparent  strabismus  divergens  is  therefore  one  of  the 
peculiarities  of  hypermetropic  eyes,  and  this  appearance  is  often 
so  deceptive  that  one  can  satisfy  himself  of  the  actual  direction 
of  the  lines  of  vision  only  by  experiment. 

The  simplest  manner  of  conducting  the  experiment  is  as  fol- 
lows. The  patient  is  directed  to  fix  an  object  about  25  cm.  dis- 
tant. The  examiner  covers  first  one  eye  with  his  hand,  and  then 
moves  it  so  as  to  cover  the  other  eye,  observing  at  the  same  time 
whether  the  eye  thus  uncovered  changes  its  position  before  it 
can  be  used  for  fixation  ;  if  it  does,  then  there  was  an  abnormal 
position, — that  is,  strabismus.  If  during  the  experiment  the  eye 
does  not  change  its  position,  there  is  no  true,  but  only  apparent 
strabismus. 

The  case  is  reversed  in  myopia.  The  smallness  of  the  angle  oc' 
causes  an  apparent  strabismus  convergens.  Often,  upon  trying 
the  experiment  just  described,  it  is  found  that  there  is  apparent 
strabismus  convergens,  but  at  the  same  time  actual  divergence  of 
the  visual  axes. 


AFFECTIONS   OF  THE   OCULAR  MUSCLES. 


THE     MOVEMENTS     OF     THE     EYES,    AND     THE     LAWS     OF 

DIPLOPIA. 

The  movements  of  the  eyes  take  place  about  axes  which  are 
assumed  all  to  intersect  each  other  at  a  point  called  the  centre  of 
rotation.  Many  investigations  have  been  made  with  reference  to  the 
situation  of  this  point,  but  they  have  led  to  somewhat  contradic- 
tory conclusions.  This  disagreement  is  due  partly  to  the  different 
methods  of  examination  and  partly  to  differences  in  the  eyes  ex- 
amined. Starting  with  the  fact  that  ametropia  depends  princi- 
pally upon  the  length  of  the  visual  axis,  Donders  and  Doyer 
made  a  series  of  experiments  to  determine  the  position  of  the 
centre  of  rotation  in  the  various  conditions  of  refraction.  Their 
method  of  examination  was  as  follows : 

The  horizontal  diameter  of  the  cornea  and  the  angle  formed  by 
the  line  of  vision  and  the  axis  of  the  cornea  were  first  measured 
with  the  ophthalmometer.  A  fine  thread  was  then  stretched 
perpendicularly  before  the  eye,  and  it  was  observed  how  far 
the  eye  had  to  move  toward  the  right  and  left  in  order  to  bring 
first  one  margin  of  the  cornea  and  then  the  other  exactly  behind 
the  thread.  From  this  angle  and  from  the  known  length  of  the 
rotation,  the  position  of  the  centre  of  rotation  was  calculated.* 
The  results  at  which  they  arrived  were  as  follows : 

1.  In  emmetropic  eyes  the  centre  of  motion  is,  on  an  average, 
1.77  millimetres  behind  the  middle  of  the  axis  of  vision. 

2.  In  myopia  the  centre  of  motion  lies  deeper  in  the  eye,  but 
at  the  same  time,  on  account  of  the  length  of  the  sagittal  diameter, 
it  lies  also  farther  from  the  posterior  wall.  The  proportion  be- 
tween that  part  of  the  visual  axis  lying  in  front  and  that  behind 
the  centre  of  motion  is  nearly  the  same  as  in  emmetropic  eyes. 

*  Comp.  Donders,  Die  Anomalien  der  Refraction  und  Accommodation, 
i  16. 

126 


AFFECTIONS   OF   THE   OCULAK   MUSCLES.  127 

3.  Ill  hypermetropic  eyes  the  centre  of  motion  does  not  lie  so 
far  behind  the  cornea,  but  at  the  sjime  time  it  is  considerably 
nearer  than  normal  to  the  posterior  wall  of  the  eye. 

In  Figs.  30,  31,  and  32  the  position  of  the  centre  of  motion  is 
indicated  by  the  letter  d.  Donders  expressly  stated  that  these 
results  affect  only  movements  in  the  horizontal  plane,  and  left 
the  question  still  open  whether  the  movements  in  the  other  di- 
rections have  the  same  centre  of  rotation.  Later  investigations 
have  not  settled  this  question.  In  the  case  of  his  own  eyes, 
J.  J.  Miiller*  found  that  the  centre  of  motion  was  farther  back 
from  the  centre  of  the  cornea  the  higher  the  plane  of  vision  rel- 
atively to  the  position  of  the  head.  Experiments  which  Dr. 
Berlinf  made,  by  a  method  altogether  different,  led  to  the  same 
result.  On  the  contrary,  A.  W.  VolkmannJ  and  Woinow§  found 
one  and  the  same  centre  of  rotation  for  all  the  movements  of  the 
eye. 

The  movements  of  the  eye  in  a  vertical  direction  extend  through 
an  angle  of  about  90°,  in  such  a  way,  however,  that  the  move- 
ment downward  is  greater  than  the  movement  upward.  In  youth, 
the  emmetropic  eye  can  move  in  the  horizontal  direction  inward 
from  42°  to  51°,  and  outward  from  44°  to  49°. 

The  movement  of  both  eyes  is  generally  equal.  With  increase 
of  age  the  motility  diminishes.  It  is,  moreover,  to  be  noticed 
that  practice  exercises  a  marked  influence  in  the  extent  of  the 
movements  of  the  eyes. 

The  movement  inward  is  greater  when  both  eyes  are  turned 
simultaneously  toward  the  same  side  (associated  movement)  than 
when  both  eyes  are  simultaneously  directed  inward  (convergent  or 
accommodative  movement).  From  this  it  follows  that  during  the 
movement  of  convergence  not  only  the  recti  interni  muscles,  but 
also  the  recti  externi,  are  innervated!  The  tension  of  the  muscles 
of  the  eye  is  greater  during  convergence  than  it  would  be  were 
one  eye  to  be  held  in  the  same  position  and  the  other  turned  in  a 
direction  parallel  to  it.  The  point  of  intersection  of  the  visual 
axes  during  the  strongest  convergence  in  emmetropia  lies  at  a 

*  Arch.  f.  Ophth.,  B.  xiv.  3,  pag.  183. 

f  Dr.  E.  Berlin  in  Palermo,  Arch.  f.  Ophth.,  B.  xvii.  2,  pag.  154. 

X  Berichte  der  Konigl.  sachs.  Gesellschaft  der  Wissenschaften,  6  Feb.  1869. 

§  Arch.  f.  Ophth.,  B,  xvi.  1,  pag.  243. 


128 


AFFECTIONS    OF    THE    OCULAR    MUSCLES. 


distance  of  from  6  to  8  centimetres.  Fig.  33  shows  the  average 
results  of  experiments  upon  the  movements  of  emmetropic  eyes ; 
it  is  reduced  to  one-third  the  natural  size. 

The  continuous  lines  indicate  the  direction  of  the  lines  of 
vision ;  the  dotted  lines  are  drawn  perpendicularly  to  the  centre 
of  the  cornea.  0  P  and  0'  P'  re2)resent  parallel  lines  of  vision. 
The  maximum  of  divergence  caused  by  prisms  with  their  refract- 

FiG.  33.* 


ing  angles  turned  outward  is  indicated  by  the  lines  0  D  and 
0'  D'  for  the  visual  axes,  and  0  d  and  0'  d'  for  the  axes  of  the 
cornea.  The  direction  of  the  lines  of  vision  during  the  greatest 
movement  outward  is  indicated  by  the  lines  0  E,  0'  E',  and 
during  the  greatest  movement  inward  by  the  lines  0  J  and  0'  I'. 
O  e,  0'  e'  and  0  i,  0'  i'  show  the  corresponding  positions  of  the 
corneal  axes.  C  is  the  nearest  point  attained  during  the  maximum 
of  convergence ;  it  lies  considerably  farther  from  the  eyes  than 
the  point  at  which  the  lines  0  J  and  0'  I'  intersect. 

In  full  accord  with  the  above  are  the  facts  shown  by  Hering,t 
that  the  movement  of  the  right  eye  to  the  right  and  the  left  eye 
to  the  left  is  less  in  near  than  in  far  vision,  and  that  the  field  of 
vision  becomes  smaller  the  nearer  it  lies  to  the  eye. 

The  position  of  the  eye  is  not  absolutely  determined  by  the  di- 
rection of  the  line  of  vision, — that  is,  the  line  which  connects  the 


*  Nach  Schuurmann,  Vifde  Verslag,  pag.  44. 

f  Die  Lehre  vom  binoculareii  Sehen,  pag.  11,  Leipzig,  1868. 


INNERVATION   OF   THE    OCULAR    MUSCLES.  129 

point  fixed  and  the  centre  of  rotation  of  the  eye, — for  the  eye  may 
revolve  about  this  axis  and  the  position  of  the  axis  be  unchanged. 
Such  movements  of  the  eye  are  called  wheel  rotations  (Raddrehun- 
gen),  because  the  iris  revolves  like  a  wheel.  Investigations  upon 
this  subject  have  established  the  law,  first  laid  down  by  Donders, 
that  for  ev^ery  position  of  the  axis  of  vision  relatively  to  the  head 
there  is  a  determined  and  unchangeable  limit  to  the  degree  of 
revolution  of  the  eye  upon  this  axis.  The  inclination  of  the 
meridians,  under  normal  relations,  is  never  so  great  as  occurs  in 
consequence  of  pathological  conditions  of  the  ocular  muscles. 

Under  physiological  relations  the  innervation  of  the  eye  is 
always  so  regulated  as  to  insure  binocular  single  vision.  If  we 
wish  to  look  directly  at  an  object,  to  which  our  attention  is  called, 
we  turn  our  eyes  in  such  a  direction  that  the  image  will  be  cast 
upon  the  fovea  centralis,  physiologically  the  most  sensitive  part 
of  the  retina.  The  symmetrical  position  of  the  physiological  cen- 
tres of  the  retina  is  the  anatomical  ground  for  binocular  vision. 
If  a  distant  object  be  fixed  with  parallel  lines  of  vision,  and  the 
attention  be  then  directed  to  a  second  object  lying  to  one  side  of 
the  first,  the  retinal  image  of  this  second  object  will  be  thrown  in 
both  eyes  at  an  equal  distance  from  the  macula  lutea,  and  in  order 
to  fix  this  object  both  eyes  must  move  through  an  equal  angle. 
Consequently,  equal  innervation  on  both  sides  is  necessary  for  the 
symmetrical  movements  of  the  eyes.  The  case  is,  of  course,  the 
same  when  the  object  fixed  approaches  the  median  Kne. 

But  Hering*  has  further  shown  that  an  equal  innervation  of 
the  two  eyes  is  required  to  direct  them  upon  a  near  as  well  as  a 
far  object  lying  to  one  side  of  the  median  line.  To  illustrate :  let 
the  eyes  at  first  be  directed  upon  a  far  point,  so  that  the  lines  of 
vision  are  parallel.  If  now  the  sight  be  directed  upon  a  nearer 
point,  one  lying  to  the  left  of  the  median  plane  and  upon  the  line 
of  vision  of  the  left  eye,  then  will  the  left  eye  have  to  change  its 
accommodation,  but  not  the  direction  of  its  line  of  vision,  while 
the  right  eye  in  order  to  adjust  itself  upon  the  fixed  point  must 
execute  a  movement  of  convergence.  But  even  in  such  a  case  the 
impulse  of  innervation  imparted  to  the  ocular  muscles  is  divided 
equally  between  both  eyes.     Both  receive  an  equally  strong  im- 

*  Hering,  Die  Lehre  vom  binocularen  Sehen,  ^  4,  Leipzig,  1868. 


130  INNERVATION   OF   THE   OCULAR   MUSCLES. 

pulse  toward  an  accommodative  (converging)  movement,  and  at 
the  same  time  toward  an  associated  movement,  to  the  left.  The 
left  eye  receives  at  the  same  time  two  opposite  and  equally  strong 
impulses;  consequently  it  yields  to  neither  of  them.  In  the  right 
eye  the  equally  strong  impulses  both  act  in  the  same  direction  and 
move  it  to  the  left. 

Now,  that  it  is  actually  true  in  the  case  just  described  that  two 
antagonistic  muscles  are  called  into  activity,  is  shown  by  a  slight 
twitching  to  and  fro  of  the  eye,  which  can  be  observed  by  a  second 
person.  The  two  concurring  innervations  acting  upon  the  left 
eye,  during  this  movement,  are  not  so  exactly  balanced  but  that 
an  interchangeable  momentary  preponderance  of  the  one  muscle 
over  the  other  may  occur.  This  twitching  becomes  gradually  less 
perceptible  if  one  practise  such  experiments.  That  such  twitch- 
ings  do  occur  at  all,  is  proof  that  the  innervation  aifects  not  only 
the  right  eye,  but  the  left  eye  as  well,  although  the  left  eye  is 
already  directed  upon  the  point  fixed. 

The  laws  of  the  associated  action  of  muscles,  which  become  es- 
tablished in  individuals  through  practice  and  habit,  gradually  by 
hereditary  transmission  become  congenital  characteristics.  It  may 
indeed  be  said  that  the  laws  which  in  general  govern  the  movements 
of  the  eyes,  prevail  for  the  most  part  as  congenital  compulsions, 
just  as  pathological  relations  of  the  ocular  muscles  and  their  inner- 
vation may  be  transmitted  to  offspring.  On  the  other  hand,  it 
can  be  proved  that  in  the  interest  of  binocular  vision  movements  of 
the  eyes  can  be  caused  which  never  occur  under  normal  relations, 
particularly  divergence  and  diiferences  in  level  of  the  visual  axes. 
If  when  viewing  a  distant  object  a  prism  of  from  6  to  8  degrees 
be  placed  before  the  eye,  with  the  refracting  angle  turned  outward, 
the  retinal  image  will  be  thrown  to  the  median  side  of  the  macula 
lutea.  Diplopia  occurs,  but  it  gradually  disappears,  because  the 
eye  performs  a  partial  revolution,  by  which  the  macula  lutea  is 
moved  inward  and  the  cornea  outward.  The  divergence  which 
can  be  effected  in  this  way  is  in  emmetropia  on  an  average  4°. 
It  has  no  influence  upon  the  maximum  of  divergence  attainable, 
whether  a  prism  of  8°  (which  causes  a  refraction  of  about  4°)  be 
placed  before  only  one  eye,  or  whether  the  effect  of  the  prisms  be 
divided  upon  both  eyes  by  placing  in  front  of  each  a  prism  of 
perhaps  4°,  with  the  refracting  angle  turned  outward.     This  fact 


OVERCOMING   PRISMS.  131 

also  proves  that  the  impulse  of  innervation  is  equally  divided  be- 
tween the  two  eyes,  so  that  when  the  prism  is  applied  to  only  one 
eye,  although  only  that  eye  deviates  outward,  still  the  impulse  of 
innervation  extends  to  both  eyes. 

The  act  by  which  the  compensating  revolution  of  the  eye  does 
away  with  the  diplopia  produced  by  prisms  is  generally  called  the 
"overcoming  of  prisms."  Starting  from  a  parallel  position  of  the 
visual  axes,  emmetropes  are,  on  an  average,  able  to  overcome 
prisms  of  8°,  which  is  equivalent  to  a  divergence  of  the  visual 
axes  of  4°.  The  axes  of  the  cornea,  which  in  emmetropic  eyes 
form  an  angle  of  5°  with  the  line  of  vision,  diverge  at  an  angle  of 
10°  when  the  visual  axes  are  parallel,  and  at  an  angle  of  about 
14°  when  the  maximum  of  divergence  is  reached.  In  hyperme- 
tropia,  according  to  Schuurmann,  the  divergence  of  the  visual 
lines  attainable  by  prisms  is  less  (on  an  average  2.8°) ;  but  since 
at  the  same  time  the  deviation  of  the  line  of  vision  from  the  centre 
of  the  cornea  is  greater  (on  an  average  7.5°),  the  divergence  of 
the  corneal  axes  is  greater  than  in  emmetropic  eyes  (on  an  average 
17.8°).  In  myopia,  stronger  prisms  can  be  overcome  than  in  em- 
metropia.  The  maximum  attainable  divergence  of  the  visual  axes 
is  on  an  average  5.8°.  Although  in  myopia  the  line  of  vision  in- 
tersects the  cornea  nearer  its  middle  than  in  emmetropia,  the  pos- 
sible divergence  attainable  by  the  corneal  axes  is  greater  than  in 
emmetropia.  In  some  cases  the  deviation  of  the  line  of  vision 
from  the  centre  of  the  cornea  may  be  actually  negative, — that  is, 
the  line  of  vision  intersects  the  cornea  to  the  outer  side  of  its 
middle  point,  so  that  with  divergence  of  the  visual  lines  there  is 
still  convergence  of  the  corneal  axes.  For  this  reason,  in  the 
cases  examined  by  Schuurmann,  the  average  attainable  divergence 
of  the  corneal  axes  was  about  9°,  or  something  less  than  for  em- 
metropic eyes. 

Prisms  with  their  refracting  angles  turned  inward  are  overcome 
by  convergence  in  a  similar  manner ;  a  contraction  of  the  pupil 
and  a  tension  of  accommodation  occur  at  the  same  time.  The 
indistinctness  of  vision,  caused  by  this  tension  of  accommodation, 
may  be  relieved  up-  to  a  certain  degree  by  the  accommodation  ad- 
justing itself  for  the  relative  far  point  corresponding  to  the  given 
degree  of  convergence.  The  limits  within  which  this  can  be 
done  are  determined  by  the  laws  governing  the  relative  range  of 


132  DIPLOPIA. 

accommodation  (see  p.  19).  Upon  abandoning  distinct  retinal 
images,  and  after  some  practice,  one  can  overcome  very  strong 
prisms  with  their  refracting  angles  turned  inward,  even  up  to  the 
greatest  degree  of  convergence  attainable  under  any  circumstances. 

These  are  movements  of  the  eyes  with  which  we  are  more  or 
less  familiar.  We  make  the  movement  of  convergence  so  often 
in  our  daily  occupations,  that  we  find  no  difficulty  in  doing  it 
under  the  influence  of  prisms.  Divergence  of  the  visual  axes 
never  occurs  under  normal  relations ;  but  we  have  learned  as 
often  as  we  pass  from  convergence  to  parallelism  to  call  both 
externi  muscles  simultaneously  into  action,  and  this  action  will 
extend  somewhat  beyond  the  normal  limit  if  a  demand  is  made 
upon  it  in  the  interest  of  binocular  single  vision.  The  case  is 
altogether  different  when  we  provoke  double  images,  standing  in 
different  horizontal  planes,  by  means  of  prisms  with  the  refracting 
angle  turned  upward  or  downward,  and  which  are  united  by 
change  of  level  of  the  visual  lines.  The  ordinary  motions  of  the 
eye  present  no  analogy  for  this  case,  and  under  physiological 
relations  one  line  of  vision  cannot  deviate  perpendicularly  more 
than  IJ  or  2  degrees  from  the  direction  of  the  other, — that  is, 
prisms  of  from  3°  to  4°  are  the  strongest  which  can  be  overcome 
by  deviations  in  a  perpendicular  direction.  One  can  learn  by  prac- 
tice, and  by  beginning  with  prisms  in  a  horizontal  and  gradually 
turning  them  to  a  vertical  position,  to  overcome  prisms  of  from 
6°  to  8°.  Under  pathological  conditions,  especially  with  insuffi- 
ciency of  the  internal  recti  muscles,  much  stronger  prisms  acting 
in  a  vertical  direction  are  often  overcome. 

The  diplopia,  which  we  can  provoke  by  physiological  experi- 
ments, serves  to  explain  almost  all  cases  of  pathological  diplopia, 
upon  the  basis  of  the  so-called  empirical  theory  of  vision.  If  we 
fix  a  certain  object  with  the  right  eye,  then  a  second  object  lying 
to  the  right  of  the  first  will  cast  its  image  on  the  median  half  of 
the  retina.  Impressions  made  upon  the  median  half  of  the  right 
retina  are  referred  to  objects  lying  to  the  right  of  the  fixation- 
point.  For  the  same  reason,  retinal  images  on  the  temporal  half 
of  the  right  eye  are  referred  to  objects  to  the  left  of  the  fixation- 
point.  For  the  left  eye  the  relations  are  of  course  exactly  sym- 
metrical. 

Applying  this  principle  at  the  same  time  to  both  eyes,  we  have 


DIPLOPIA. 


133 


the  laws  for  the  occurrence  of  homonymous  and  of  crossed  double 
images. 

In  Fig.  34,  suppose  both  eyes  to  be  directed  upon  the  point  6, 
then  will  the  image  a'  of  the  point  a  be  cast  in  both  eyes  upon 
the  median  half  of  the  retina,  and  from  what  has  been  said  it  fol- 
lows that  the  image  a' ,  in  the  left  eye,  will  be  referred  to  an  object 

Fig.  34. 


to  the  left  of  the  point  6,  and  the  image  a' ,  in  the  right  eye,  to 
an  object  to  the  right  of  6.  The  point  a  appears  in  double 
homonymous  images.  Relatively  to  the  point  a  the  visual  axes 
converge,  since  they  intersect  at  6.  Convergence  of  the  visual 
axes  causes  homonymous  double  images,  and  conversely  we  can,  as 
a  rule,  diagnose  convergence  of  the  visual  axes  from  homonymous 
double  images.  On  the  contrary,  impressions  made  on  the  tem- 
poral half  of  the  retina  are  projected  by  the  right  eye  to  the  left, 
and  by  the  left  eye  to  the  right  of  the  fixation-point.  If  a  is  the 
point  fixed,  then  6  casts  its  image  h'  in  both  eyes  upon  the  tempo- 
ral half  of  the  retina ;  the  point  6  appears  double,  and  the  image 
in  the  right  eye  will  be  seen  to  the  left,  and  the  image  in  the  left 
eye  to  the  right,  of  the  point  a.  There  is  crossed  diplopia.  Rela- 
tively to  the  point  h  the  visual  axes  are  divergent ;  consequently 
divergence  of  the  visual  axes  causes  crossed  double  images,  and  con- 
versely divergence  of  the  visual  axes  may  be  inferred  from  diplopia. 
The  results  of  this  easy  experiment  may  be  still  further  con- 
firmed by  prisms.  If  we  place  before  the  right  eye  a  prism  with 
the  refracting  angle  turned  outward,  then  will  the  image  be  so 
displaced  that  the  point  fixed  with  the  left  eye  will  cast  its  image 
in  the  right  eye  to  the  median  side  of  the  macula  lutea,  and 
homonymous  diplopia  occurs.     If,  on  the  contrary,  there  exist 


134  PARALYSIS   OF  THE   OCULAR   MUSCLES. 

homonymous  diplopia  in  consequence  of  a  false  position  of  the 
right  eye  (converging  squint),  we  can,  by  the  use  of  the  proper 
prisms  with  their  refracting  angles  turned  inward,  move  the  image 
so  far  toward  the  temporal  side  that  it  will  fall  upon  the  macula 
lutea.  In  this  way  we  again  establish  the  possibility  of  binocular 
single  vision,  and  this  possibility  is  realized  whenever  the  normal 
binocular  act  takes  place.  From  what  has  been  said,  it  follows 
that  we  can  correct  homonymous  diplopia  by  prisms  with  their  bases 
turned  outward,  and  crossed  diplopia  by  prisms  with  their  bases 
turned  inward. 

In  accordance  with  what  has  been  said  above,  concerning  the 
action  of  prisms,  it  is  not  necessary  to  place  the  correcting  prism 
before  the  deviating  eye :  it  is  generally  better  to  place  prisms  of 
equal  strength  before  both  eyes. 

The  same  is  true  w^hen  the  double  images  are  on  a  different 
level.  If,  for  instance,  the  retinal  image  of  the  object  fixed,  fall 
in  one  eye  below  the  macula  lutea,  it  will  be  seen  by  that  eye 
above  the  object.  We  can  cause  it  to  approach  the  macula  lutea, 
and  can  restore  binocular  single  vision  by  means  of  a  prism  with 
its  base  turned  upward.  If  one  wishes  to  divide  the  action  of 
the  prisms  upon  both  eyes,  the  other  eye  is  to  be  provided  with  a 
prism  with  its  base  turned  downward. 

PARALYSIS   OF   THE   OCULAR   MUSCLES. 

The  nerves  which  control  the  movements  of  the  eyes  are  dis- 
tributed very  un-uniforraly  to  the  muscles.  While  the  nervus 
abducens  and  the  nervus  trochlearis  innervate  only  a  single  muscle 
each,  all  the  other  muscles  of  the  eye,  together  with  the  levator 
palpebrse  superioris,  depend  upon  the  nervus  oculo-motorius. 
Moreover,  the  sympatheticus  exercises  an  influence  upon  the 
muscles  of  the  iris,  and  upon  those  smooth  muscular  fibres  of  the 
lids  which  H.  Miiller  discovered. 

A  special  consideration  of  the  paralyses  of  the  ocular  muscles 
will  be  conducted  with  reference  to  the  nervous  distribution. 

PARALYSIS   OF   THE   ABDUCENS. 

The  paralysis  of  the  rectus  externus  muscle  causes  a  limitation 
in  the  outward  movement  of  the  eye,  which  varies  greatly  in 


PARALYSIS   OF   THE   ABDUCENS.  135 

proportion  to  the  degree  of  the  paralysis.  In  complete  paralysis 
the  eye  can  be  turned  outward  scarcely  beyond  the  middle  of  the 
palpebral  fissure,  while  with  incomplete  paralysis  movement  is 
often  so  well  maintained  that  the  eye  can  be  turned  outward 
almost  to  the  normal  limit,  but  only  for  a  short  time,  and  with 
a  twitching  movement.  The  estimation  of  the  loss  of  motility 
is  made  easy  by  observing  that  portion  of  the  sclera  between  the 
cornea  and  the  external  canthus,  which  remains  visible  when  the 
eye  turns  outward  to  its  farthest  limit ;  this  free  scleral  space  is 
of  a  size  easily  recognizable.  More  important,  however,  is  it  to 
compare  the  motility  of  the  two  eyes,  since  the  degree  of  move- 
ment in  general  and  under  normal  conditions,  varies  greatly  in 
different  individuals.  While  many  persons  can  move  their  eyes 
through  so  great  an  arc  that  the  limbus  of  the  cornea  disappears 
behind  the  external  canthus,  there  always  remains  visible,  in  the 
case  of  others,  a  segment  of  the  sclera  more  than  a  millimetre  in 
breadth.  Nevertheless,  aside  from  exceptional  cases  which  are 
explained  by  striking  differences  in  the  anatomical  structure  of  the 
eye  (for  instance,  a  high  degree  of  unilateral  myopia),  the  move- 
ments of  the  two  eyes  are  equal,  so  that  a  difference  in  the  move- 
ments, as  a  rule,  should  be  referred  to  a  muscular  paralysis  of  that 
eye  which  falls  behind  in  associated  movements. 

Even  when  the  defect  of  absolute  motion  is  too  slight  to  be 
observed  with  certainty,  the  disturbances  in  associated  movements 
are  apparent.  We  will  suppose  a  case  of  paralysis  of  the  abdu- 
cens  on  the  right  side,  then  in  the  associated  movement  toward 
the  left,  the  muse,  rectus  externus  of  the  left  and  the  rectus  in- 
ternus  of  the  right  eye  will  act  equally  and  together;  in  the 
movement  toward  the  right,  on  the  contrary,  the  impulse  of 
innervation  divided  equally  between  the  two  eyes  is  sufficient  for 
the  healthy  rectus  internus  of  the  left,  but  not  for  the  paralytic 
rectus  externus  of  the  right  eye.  The  left  eye  can  follow  the 
movement  toward  the  right  of  the  object  fixed,  but  the  right  eye 
falls  behind  in  its  movement,  even  before  it  attains  the  limit  of 
its  absolute  motility ;  it  surrenders  fixation,  and  an  abnormal  con- 
vergence of  the  visual  axes  and  consequent  homonymous  diplopia 
occur.  If  now  the  unaffected  left  eye  be  covered,  the  right  eye, 
before  it  reaches  the  limit  of  its  absolute  motility,  can  direct  itself 
upon  the  object  fixed,  but  of  course  only  by  a  greater  effort  than 


136  PARALYSIS   OF   THE   ABDUOENS. 

under  normal  conditions.  Since,  however,  the  impulse  of  inner- 
vation acts  equally  upon  both  eyes,  the  healthy  rectus  internus  of 
the  left  eye  will  be  just  as  strongly  innervated  as  is  the  paralytic 
rectus  externus  of  the  right  eye,  consequently  the  associated  move- 
ment of  the  left  eye  is  relatively  too  great,  and  there  occurs  a 
still  stronger  convergence  than  when  the  healthy  eye  is  used  for 
fixation. 

Often  the  antagonist  of  the  paralyzed  muscle  becomes  shortened, 
and  the  eflPect  is  an  abnormal  convergence  for  every  part  of  the 
field  of  vision.  This  is  due  to  the  fact  that  the  antagonist  is 
always  in  action.  So,  for  instance,  in  paralysis  of  the  abducens 
on  the  right  side,  the  rectus  internus  of  the  eye  affected  is  called 
into  activity,  both  in  the  associated  movement  toward  the  left  and 
during  convergence,  without  the  occurrence  of  any  counterbal- 
ancing tension  on  the  part  of  the  abducens.  In  many  eases  this 
paralytic  squint  often  develops  at  a  very  early  stage  of  the  dis- 
ease; it  occurs  in  the  majority  of  cases  of  paralysis  of  the  ab- 
ducens. Still,  there  are  cases  in  which,  during  the  whole  course 
of  the  paralysis,  a  true  paralytic  squint  does  not  develop,  but 
convergence  occurs  only  in  those  positions  W'hich  call  for  the 
activity  of  the  paralyzed  muscle.  It  is  highly  probable  that  the 
occurrence  or  non-occurrence  of  paralytic  squint  depends  upon 
the  pre-existing  relative  elasticity  of  the  ocular  muscles. 

The  recognition  of  paralysis  of  the  abducens  presents  no  diffi- 
culties. The  limitation  of  motion  is  often  so  apparent  that  it 
alone  assures  the  diagnosis.  If  this  limitation  be  so  slight  that 
there  is  still  some  doubt,  the  test  by  double  images  is  a  very 
reliable  one.  Diplopia  occurs  whenever  vision  is  turned  in  a 
direction  for  which  the  action  of  the  abducens  is  insufficient, 
and  the  distance  between  the  double  images  is  increased,  the 
greater  the  demand  made  upon  the  paralyzed  muscle.  The  best 
method  of  conducting  the  test  by  double  images  is  as  follows.  A 
sharply  defined,  easily  perceived  fixation-object  is  employed,  the 
flame  of  a  candle  is  the  best:  one  eye  is  covered  with  a  colored 
glass,  say  a  bright  red.  The  difference  in  color  of  the  two  images 
makes  it  easy  for  the  patient  to  see  them  both,  and  enables  the 
examiner  to  determine  at  once  to  which  eye  the  respective  images 
belong.  We  will  suppose,  again,  a  paresis  of  the  abducens  on  the 
right  side,  in  the  first  place  without  any  contraction  of  its  antag- 


PARALYSIS   OF   THE    ABDUCENS.  137 

onist;  then  there  will  be  single  vision  in  the  left  half  of  the  visual 
field,  up  to  the  median  line  or  even  beyond  it,  till  the  object  fixed 
comes  opposite  the  right  eye.  The  more  vision  is  directed  toward 
the  right,  so  much  the  more  does  the  right  eye  fall  relatively 
behind  the  left:  homonymous  double  images  appear,  whose  dis- 
tance from  each  other  increases  the  more  the  candle  is  moved 
toward  the  right. 

The  boundary-line  which  separates  the  region  of  single  vision 
from  that  of  diplopia  may  lie  upon  the  same  side  of  the  median 
plane  if  the  degree  of  paresis  is  slight,  or  it  will  lie  beyond  it  if 
secondary  contraction  of  the  antagonist  has  occurred.  This  bound- 
ary-line, moreover,  is  generally  not  vertical,  but  so  inclined  that 
the  region  of  diplopia  is  more  extensive  below  than  above.  Since 
nearly  all  objects  in  the  upper  half  of  the  visual  field  are  seen  with 
parallel  axes  of  vision,  while  downward  vision  is  generally  asso- 
ciated with  convergence,  we  accordingly  often  find  under  patho- 
logical conditions  an  inclination  to  parallelism  or  divergence  while 
looking  upward,  and  to  convergence  when  looking  downward. 

Finally,  the  line  of  demarcation  between  single  and  double 
vision  is  no  fixed  and  unchangeable  one,  for  its  position  varies 
according  to  whether,  in  making  the  examination,  one  starts  from 
the  region  of  single  or  of  double  vision.  In  the  first  case,  binoc- 
ular single  vision  is  maintained  as  long  as  the  relations  of  inner- 
vation permit,  while  conversely,  if  the  object  fixed  be  moved 
gradually  from  the  region  of  double  vision  toward  the  other  side, 
the  double  images  still  persist  when  the  position  has  come  to  be 
that  in  which  single  vision  can  be  perfectly  well  maintained.  The 
impulse  toward  binocular  single  vision  resists  the  separation  of  the 
double  images  as  long  as  possible,  but  its  effect  is  not  so  great 
when  called  upon  to  unite  double  images  already  existing.  The 
influence  which  the  requirements  of  binocular  vision  exercise  upon 
the  maintenance  of  a  proper  position  of  the  eyes,  is  early  seen  in 
those  cases  of  receding  muscular  paralysis  in  which,  in  the  greater 
part  of  the  field,  single  vision  has  been  restored.  If,  for  instance, 
in  such  a  case  of  paresis  of  the  abducens,  double  images,  standing 
one  higher  than  the  other,  are  produced  by  prisms  acting  vertically, 
the  images  will  show  near  the  boundary  of  binocular  single  vision 
not  only  a  difference  in  level  bat  a  homonymous  lateral  separa- 
tion.    This  proves  that  under  these  circumstances  single  vision 

10 


138  PAEALYSLS    OF   THE    ABDUCENS. 

can  be  maintained  only  by  an  unusually  strong  impulse  of  inner- 
vation. The  occasion  for  this  impulse  no  longer  exists  when  ver- 
tically refracting  prisms  render  the  uniting  of  the  double  retinal 
images  impossible. 

If  paralytic  strabismus  convergens  has  developed,  diplopia 
extends  over  all  or  nearly  all  the  field  of  vision.  The  diagnosis 
between  paralytic  and  typical  strabismus  convergens  is  not  diffi- 
cult, although  a  squint  originally  paralytic  may  become  a  typical 
one, — that  is,  when  strabismus  convergens  remains  after  recovery 
from  the  paralysis.  We  class  as  paralytic  squint  all  those  cases 
in  which  there  are  signs  of  paralysis  of  the  ocular  muscles,  recog- 
nizable by  a  limitation  of  movement  and  the  behavior  of  the 
double  images.  If  diplopia  exist  in  typical  strabismus,  the  distance 
between  the  two  images  remains  nearly  the  same  in  every  part  of 
the  field,  while  in  paralytic  strabismus  there  is,  it  is  true,  diplopia 
in  the  entire  field  of  vision,  but  the  distance  between  the  images 
increases  the  greater  the  demand  made  upon  the  paralyzed  muscle. 

It  should  be  mentioned  that  in  some  cases  the  patients  do  not 
complain  of  diplopia,  but  only  of  indistinct  vision.  The  impres- 
sion is  that  they  see  one  object  through  another,  since  each  eye 
sees  a  different  portion  of  the  field  of  vision,  while  it  is  a  matter 
of  observation  to  find  out  which  position  of  the  field  of  vision 
belongs  to  each  one  of  the  double  images. 

This  form  of  indistinct  vision  is  generally  called  masked  double 
vision  (verkapptes  Doppeltsehen).  It  is  characterized  by  the  fact 
that  each  eye  separately  sees  distinctly,  and  the  disturbance  occurs 
only  in  binocular  vision.  In  most  cases  of  this  kind  the  diplopia, 
as  such,  may  be  brought  to  the  attention  of  the  patient  by  placing 
in  front  of  one  eye  a  red  glass  and  using  as  a  fixation-object  the 
flame  of  a  candle.  The  same  symptoms  can,  of  course,  occur  in 
all  the  paralyses  of  the  ocular  muscles. 

A  very  curious  condition  is  presented  by  those  cases  in  which, 
on  account  of  defective  vision  in  the  other  eye,  the  one  affected 
with  paralysis  is  used  for  fixation.  Let  us  suppose  again  a  case 
of  paralysis  of  the  abducens  on  the  right  side,  but  with  defective 
vision  in  the  left  eye, — then,  for- the  reasons  set  forth  on  page  136, 
the  left  eye  will  experience  a  strong  secondary  deviation.  The 
patient  presents  himself  to  us  with  strong  strabismus  convergens 
on  the  left  side,  with  free  movement  of  that  eye,  which,  at  first. 


PARALYSIS   OF   THE   ABDUCENS.  139 

will  therefore  appear  to  be  the  affected  one.  Nevertheless,  a  criti- 
cal comparison  of  the  movements  of  the  two  eyes  and  the  behavior 
of  the  double  images  (when  the  weak-sighted  eye  has  sufficient 
power  of  vision)  enables  one  to  locate  the  seat  of  the  paralysis  on 
the  right  side. 

One  symptom  occurring  with  other  paralyses  of  the  ocular 
muscles  is  generally  very  marked  in  these  cases.  The  face  is 
turned  toward  the  side  of  the  paralyzed  muscle,  partly  by  that 
position  to  compensate  for  the  loss  of  its  action,  and  partly  to 
move  the  field  of  single  vision  as  much  as  possible  to  the  front. 

Most  cases  of  paresis  of  the  abducens  may  be  ascribed  to 
rheumatic  causes;-  these  cases  are  often  preceded  by  rheumatic 
pains  in  the  head  on  the  side  affected,  especially  in  the  temporal 
region ;  or  they  may  persist  after  the  occurrence  of  the  paralysis. 
A  less  frequent  cause  is  syphilis.  In  many  cases  there  are  local 
causes  in  the  orbit,  and  finally  paralysis  of  the  abducens,  as  of 
the  ocular  muscles  in  general,  may  occur  as  a  symptom  of  cere- 
bral or  spinal  disease;  it  is  often  indeed  the  first  symptom  of 
such  a  condition.  Some  cases  are  congenital,  or  they  develop 
without  any  known  cause  during  childhood. 

The  prognosis  is  generally  favorable  provided  the  patient  be 
subjected  to  proper  treatment.  In  cases  which  recover  spontane- 
ously the  condition  generally  lasts  two  months.  The  secondary 
contraction  of  the  antagonistic  muscle  generally  disappears  simul- 
taneously with  the  paralysis  ;  if  the  paralysis  does  not  entirely 
recover,  there  is  more  probability  of  permanent  convergent  sguint. 
In  such  cases  the  diploj)ia  does  not  generally  entirely  disa^jpear, 
but  it  becomes  less  annoying. 

The  treatment  is  to  be  directed  principally  against  the  cause  of 
the  disease.  Rheumatic  paralyses  require,  in  the  first  place,  pro- 
tection from  all  injurious  influences.  The  patient  should  remain 
in  a  warm  room ;  should  avoid  changes  of  temperature,  keeping 
the  affected  side  of  the  head  covered  with  cloths  or  wadding; 
diaphoretics,  and  even  emetics,  are  recommended  in  the  earliest 
stages  of  the  disease.  The  rheumatic  pains  in  the  temple,  or 
anywhere  in  the  affected  half  of  the  head,  which  are,  at  first, 
often  ])resent,  are  relieved  in  the  most  satisfactory  manner  by 
local  blood-letting.  In  the  further  course  of  the  disease  deriva- 
tive remedies  are  indicated, — vesications  on  the  neck,  painting  the 


140  PARALYSIS   OF   THE   ABDUCENS. 

forehead  and  temple  with  tincture  of  iodine,  etc.  Electricity  also 
does  good  service  in  the  later  periods  of  the  disease,  and  although 
the  electric  treatment,  on  account  of  the  deep  position  of  the 
muscle,  cannot  act  in  so  direct  a  manner  as  in  the  case  of  other 
muscles,  still,  some  part  of  the  electric  current  seems  to  be  able  to 
reach  it. 

The  indications  suggested  by  the  presence  of  syphilitic,  cerebral, 
or  spinal  disease,  belong  in  the  province  of  special  pathology,  and 
need  not  here  be  discussed. 

To  relieve  the  annoyance  of  diplopia,  a  pair  of  spectacles  may 
be  worn  which  cover  the  affected  eye  with  a  ground  glass.  The 
idea  suggests  itself  of  uniting  the  double  images  by  means  of 
prisms,  but  it  is  seldom  practicable.  The  principal  reason  for 
this  is  that,  even  in  a  case  of  slight  paralysis,  the  distance 
between  the  double  images  is  too  great  to  admit  of  their  being 
united  by  prisms  which  could  be  worn  as  spectacles.  Prisms  of 
more  than  6°  or  7°  can  scarcely  be  worn  for  this  purpose,  partly 
because  of  their  weight,  partly  because  of  their  chromatic  aberra- 
tion. Even  if  both  eyes  were  provided  symmetrically  with  such 
prisms,  the  effect  would  be  that  of  a  prism  of  12°  or  14°,  which 
would  generally  be  insufficient. 

Another  essential  reason  against  their  use  is,  that  the  distance 
between  the  double  images  varies  greatly  with  every  change  in 
the  direction  of  vision.  If,  for  instance,  with  paresis  of  the 
abducens  on  the  right  side  there  be  single  vision  in  the  left  half 
of  the  visual  field,  while  during  vision  directed  in  the  median 
plane  diplopia  is  present,  which  could  be  corrected  by  a  prism  of 
12°  or  14°,  it  would  still  not  be  well  to  allow  such  prismatic  spec- 
tacles to  be  worn.  On  account  of  the  increased  distance  between 
the  images  in  the  right  half  of  the  field,  they  would  not  be  suffi- 
cient to  unite  the  double  images  during  vision  in  this  direction ; 
while  in  the  left  half  of  the  field,  where  there  was  normal  single 
vision,  the  prisms  would  provoke  crossed  double  images,  and  a 
compensating  convergence  of  the  visual  axes.  Under  these  cir- 
cumstances a  secondary  contraction  of  the  antagonistic  muscle  is 
induced,  and  the  development  of  strabismus  convergens  is  favored. 

The  correction  of  the  diplopia  by  prisms  is,  then,  indicated 
only  when  there  exists  secondary  contraction  of  the  antagonistic 
muscle,  and,  as  a  consequence  of  that,  diplopia  throughout  the 


PARALYSIS    OF   THE   ABDUCENS.  141 

entire  field  of  vision.  The  prisms  should  be  chosen  of  such  a 
strength  as  to  correct  only  that  part  of  the  diplopia  which  is  due 
to  this  contraction  of  the  antagonist, — that  is,  they  are  to  be  chosen 
with  reference  to  a  position  of  the  eyes  in  which  no  demand  is 
made  upon  the  paralyzed  muscle.  Since,  however,  as  already 
remarked,  only  very  weak  prisms  can,  under  any  circumstances, 
be  used,  it  follows  that  they  can  be  resorted  to  only  in  cases 
which  are  very  nearly  recovered.  Under  such  circumstances  the 
use  of  prismatic  spectacles  with  their  refracting  angles  turned 
inward  is,  in  many  cases,  to  be  recommended,  because  as  the 
region  of  single  binocular  vision  is  increased  the  impulses  of 
innervation,  which  aifect  the  paralyzed  muscles  in  favor  of  binoc- 
ular single  vision,  increase  also. 

A  similar  result — that  is,  the  exercise  of  the  paralyzed  muscles 
in  the  service  of  binocular  single  vision — may  be  obtained  in  an- 
other manner.  The  patient  is  directed  to  look  at  an  object  held 
within  the  region  of  binocular  single  vision,  and  it  is  then  moved 
slowly  over  into  the  region  of  double  vision,  or,  what  has  the 
same  effect,  the  object  remains  stationary  while  the  position  of 
the  head  is  changed. 

Convergent  squint  may  exceptionally  follow,  in  spite  of  com- 
plete recovery  from  the  paralysis.  If,  in  such  cases,  both  eyes 
are  alike  in  reference  to  refraction  and  acuteness  of  vision,  stra- 
bismus convergens  alternans  generally  develops,  which  is  to  be 
relieved  by  the  tenotomy  of  one  or  both  recti  interni  muscles. 
But  convergent  squint  is  more  frequent  in  cases  of  incomplete 
recovery  from  the  paralysis.  Besides  the  tenotomy  of  the  rectus 
internus  it  may  be  necessary  to  bring  the  externus  forward. 

All  such  operations  should,  however,  be  postponed  until  the 
paralysis  is  either  completely  cured  or  has  become  so  chronic 
that  no  improvement  is  to  be  expected.  Too  early  an  operation, 
although  its  effect  is  at  first  satisfactory,  may  cause  a  deviation  in 
the  opposite  direction  after  recovery  from  the  paralysis  takes 
place. 

PARALYSIS    or    THE    OCULO-MOTORIUS. 

Complete  paralysis  of  the  oculo-motorius  presents  a  very 
striking  picture.  The  upper  lid  droops  and  covers  the  cornea ; 
the  external  canthus  is  generally  lower  than  on  the  other  side. 
If  we  raise  the  upper  lid  we  see  the  eye  generally  turned  outward, 


142  PARALYSIS   OF  THE   OCULO-MOTORIUS. 

and  it  can  be  only  partially  turned  inward, — scarcely  to  the  middle 
of  the  palpebral  fissure.  There  is  no  upward  motion  whatever,  for 
both  muscles  acting  in  that  direction,  the  rectus  superior  and  ob- 
liquus  inferior,  are  paralyzed  ;  the  downward  movement  is  effected 
only  by  the  obliquus  superior,  and  is  therefore  incomplete,  and  is 
accompanied,  especially  when  the  cornea  is  turned  outward,  by  a 
perceptible  rotation,  which  causes  the  upper  end  of  the  vertical 
meridian  to  incline  inward.  The  pupil  is  moderately  dilated  and 
accommodation  is  lost.  There  is  often  a  slight  protrusion  of  the 
eyeball  noticeable  (exophthalmus  paralyticus) ;  this  is  due  to  the 
diminished  elastic  tension  of  the  three  muscles,  innervated  by  the 
oculo-motorius,  and  which  draw  the  eyeball  backward. 

The  picture  of  a  complete  paralysis  of  the  oculo-motorius  is  so 
striking  that  it  seems  hardly  necessary  to  confirm  the  diagnosis 
by  the  test  of  double  images ;  still,  in  certain  cases  it  may  be 
desirable  to  do  so.  We  will  suppose  again  a  paralysis  on  the 
riglit  side,  by  which  all  the  branches  of  the  oculo-motorius  are 
more  or  less  affected ;  then  will  there  be,  either  in  tlie  entire 
visual  field  or  when  vision  is  directed  to  the  left,  double  crossed 
images,  whose  distance  from  each  other  increases  the  more  the 
object  fixed  is  moved  to  the  left.  When  vision  is  directed  up- 
ward the  right  eye  falls  behind,  the  crossed  double  images  sepa- 
rate from  each  other  in  a  vertical  direction,  the  distance  between 
them  increasing  the  more  vision  is  directed  upward.  In  looking 
downward,  also,  the  same  differences  in  the  level  of  the  double 
images  will  appear,  only  the  relations  will  be  reversed,  and  the 
image  in  the  right  eye  will  appear  to  stand  the  lower. 

If  there  be  only  partial  paralysis  of  the  oculo-motorius,  affect- 
ing only  certain  muscles,  while  others  are  free,  the  diagnosis  may 
become  very  complicated,  especially  if  incomplete  paralysis  affect 
both  eves  at  the  same  time.  On  the  other  hand,  the  diagnosis  is 
the  more  easily  arrived  at,  from  the  fact  that  the  levator  palpebrse 
superioris  is  seldom  unaffected,  and  its  condition  is  easily  recog- 
nized ;  the  iris  and  the  accommodation  are  often  simultaneously 
affected. 

Moreover,  every  limitation  of  movement  upward,  if  it  depend 
upon  muscular  paralysis,  must  be  referred  to  the  oculo-motorius, 
from  which  both  the  muscles  acting  upward,  the  rectus  superior 
and  obliquus  inferior,  are  innervated.     The  only  diagnostic  diffi- 


PARALYSIS   OF  THE  OCULO-MOTOEIUS.  143 

culty  is  in  connection  with  that  antagonistic  pair  of  muscles, — 
the  rectus  inferior  and  the  obliquus  superior, — the  first  being 
innervated  from  the  oculo-motorius,  while  the  second  has  its  own 
nerve.  The  diiferential  diagnosis  between  the  paralyses  of  these 
two  nerves  will  be  discussed  under  the  head  of  "  paralysis  of  the 
trochlearis." 

The  inconveniences  experienced  by  the  patients  are  diplopia 
and  paralysis  of  accommodation,  except  when,  as  is  generally  the 
case,  the  eye  is  absolutely  excluded  from  the  visual  act  by  the 
drooping  of  the  lid  (ptosis). 

If  the  affected  eye,  on  account  of  the  poorness  of  the  other,  must 
be  used  for  fixation,  the  patients  are  in  a  very  unfortunate  posi- 
tion. Not  only  the  strong  secondary  deviation  of  the  other  eye, 
which  we  have  mentioned  as  occurring  under  analogous  conditions 
in  paralysis  of  the  abducens,  but  other  more  serious  difficulties 
appear,  which  indeed  exist  and  are  evident  in  paralysis  of  the 
abducens,  but  are  there  less  annoying. 

In  all  paralyses  of  the  ocular  muscles,  Avith  fixation  by  the 
affected  eye,  the  field  of  vision  is  falsely  projected  whenever  a 
demand  is  made  upon  the  action  of  the  paralyzed  muscle.*  This  is 
most  easily  demonstrated  in  the  case  of  paralysis  of  the  abducens. 
The  patient  is  directed  to  shut  the  healthy  eye,  and  then  to  fix 
with  the  other  eye  some  object  lying  on  the  same  side  with  the 
paralyzed  muscle ;  he  is  then  directed  to  touch  quickly  with  his 
finger  the  object  fixed.  In  doing  so  he  will  project  his  hand  too 
far  on  the  paralyzed  side,  provided  he  do  not  make  the  move- 
ment so  slowly  that  it  is  controlled  and  corrected  by  vision  instead 
of  the  original  impulse.  In  order  to  give  the  eye  the  necessary 
position,  the  paralyzed  abducens  must  receive  a  stronger  impulse 
of  innervation,  which,  under  normal  conditions,  would  cause  much 
too  strong  a  contraction  of  the  muscle.  This  gives  to  the  patient 
the  impression  that  he  is  directing  his  eye  farther  outward  than 
is  really  the  case,  and  accordingly  he  displaces  his  entire  field  of 
vision  too  far  toward  the  same  side. 

Although  this  false  projection  of  the  field  of  vision  is  easily  de- 
monstrable in  paralysis  of  the  abducens,  still  it  seldom  causes  in- 
convenience, even  when  the  affected  eye  has  to  be  used  for  fixation  ; 

*  Y.  Graefe,  Arch.  f.  Ophth.,  B.  i.  1,  pag.  18. 


144  PARALYSIS    OF   THE   OCULO-MOTORIUS. 

but  the  reverse  obtains  in  the  case  of  paralysis  of  the  oculo-motorius 
on  account  of  the  number  of  muscles  affected.  The  field  of  vision 
is  in  rapid  succession  falsely  projected  in  various  directions,  ac- 
cording to  the  changes  in  the  direction  of  vision ;  it  is  first  too 
far  on  one  side,  then  too  high,  then  too  low.  The  want  of  cor- 
respondence between  the  strain  made  upon  the  ocular  muscles  and 
the  actual  movements  of  the  eye  thereby  accomplished,  causes  an 
impression  upon  the  patient  as  if  the  surrounding  objects  were  in 
motion ;  this  gives  him  the  sensation  of  dizziness,  causes  his  gait 
to  be  very  unsteady,  and  induces  total  loss  of  co-ordination  in 
rapid  movements. 

In  reference  to  the  etiology,  it  should  be  noted  that  syphilis 
is  a  relatively  frequent  cause  of  paralysis  of  the  oculo-motorius. 
Aside  from  this  it  may  be  caused,  as  may  paralyses  in  general, 
by  rheumatism,  diseases  of  the  central  nervous  system,  changes 
at  the  base  of  the  brain,  in  the  orbit,  etc. 

The  treatment  is  in  the  first  place  to  be  directed  against  the 
cause;  for  instance,  syphilis.  In  other  respects  the  treatment 
recommended  for  paralysis  of  the  abducens  is  applicable. 

If,  after  recovery  from  paralysis,  strabismus  remain,  it  is  to 
be  relieved  by  tenotomy  of  the  rectus  externus,  and  if  there  be 
very  great  loss  of  motion  on  the  side  of  the  rectus  internus,  it 
may  be  necessary  simultaneously  to  bring  the  insertion  of  that 
muscle  forward.  The  question  of  treatment  is  more  complicated 
in  cases  where  the  upward  and  downward  movements  are  only 
partially  restored.  Only  where  the  vertical  deviation  of  the  eyes 
is  very  considerable  do  we  have  the  indication  for  bringing  for- 
ward the  insertion  of  the  rectus  inferior  or  superior.  Von  Graefe* 
recommended  that  slight  defects  of  vertical  motion  be  compen- 
sated for  by  tenotomy  in  the  other  eye  of  the  muscle  acting  in  the 
same  direction,  be  it  the  rectus  inferior  or  superior.  If,  for  in- 
stance, the  right  eye  squints  upward  and  has  but  limited  move- 
ment downward,  then  a  tenotomy  of  the  rectus  inferior  in  the  left 
eye  will  cause  that  to  turn  upward  and  limit  its  movement  down- 
ward. If  a  harmonious  action  of  the  ocular  muscles  is  thus  par- 
tially, but  not  sufficiently  established,  the  insertion  of  the  rectus 
superior  of  the  right  eye  may  be  set  backward. 

*  Klin.  Monatsbl.  fiir  Augenheilk.,  1864,  pag.  1. 


PARALYSIS    OF    THE    TEOCHLEARIS.  145 

The  objection  is  made  to  this  procedure,  that  in  movements 
either  upward  or  downward  one  rectus  muscle  always  acts  in 
connection  with  one  obliquus,  while  it  is  possible  to  reach  only 
the  recti  muscles  by  a  regular  operation  ;  still,  experience  teaches 
that  after  tenotomy  of  the  rectus  inferior  or  superior,  the  incon- 
veniences dependent  upon  the  action  of  the  corresponding  obliquus 
soon  pass  away  under  the  influence  of  binocular  single  vision. 

PARALYSIS   OF    THE   TEOCHLEARIS. 

Under  physiological  conditions  the  musculus  obliquus  superior 
and  the  rectus  inferior  always  act  together;  both  turn  the  eye 
dowuM^ard,  acting  under  the  influence  of  the  will  as  a  single  muscle. 
If  now  the  action  of  the  obliquus  fail,  so  that  in  looking  down- 
ward the  rectus  inferior  alone  acts,  then,  starting  from  a  position  in 
which  the  visual  axes  are  parallel  to  the  median  plane,  the  move- 
ment will  not  be  simply  downward,  but  at  the  same  time  somewhat 
inward.  The  effect  of  the  rectus  inferior  in  moving  the  cornea 
downward  is  greatest  when  the  muscle  is  nearest  to  lying  in  the 
plane  of  the  meridian  of  its  insertion,  and  this  is  the  case  when 
vision  is  directed  outward,  thus  bringing  the  line  of  vision  and  a 
line  connecting  the  origin  and  insertion  of  the  muscle  into  the 
same  vertical  plane.  The  more,  on  the  contrary,  the  eye  turns 
inward,  the  greater  the  angle  between  the  line  of  vision  and  the 
direction  of  the  traction  of  the  muscle.  Only  a  part  of  the  force 
of  the  muscle  can  then  be  expended  in  turning  the  cornea  down- 
ward ;  the  other  part  acts  to  revolve  the  eye  about  the  axis  of 
vision.  If  in  paralysis  of  the  trochlearis  the  rectus  inferior  has 
to  act  alone  in  directing  vision  downward,  then  the  defect  in  down- 
ward movement  will  be  least  in  looking  downward  and  outward, 
and  greatest  when  looking  downward  and  inward. 

In  paralysis  of  the  obliquus  superior,  not  only  is  the  muscular 
force  which  rotates  the  eye  downward  diminished,  but  we  must 
take  into  consideration  the  elastic  resistance  which  the  antagonistic 
group  of  muscles  opposes  to  this  rotation.  There  is,  of  course,  no 
change  in  the  antagonistic  relations  between  the  rectus  inferior  and 
superior,  but  the  paralyzed  trochlearis  no  longer  counterbalances 
the  obliquus  inferior.  The  effect  of  this  is  different  in  the  dif- 
ferent directions  of  vision.  When  vision  is  directed  inward,  the 
curve  by  which  the  two  obliqui  muscles  embrace  the  posterior 


146  PARALYSIS   OF   THE   TROCHLEARIS. 

part  of  the  eyeball  very  nearly  approaches  the  form  of  a  part  of  a 
great  circle.  It  is  then  in  this  position  that  the  elastic  resistance 
of  the  obliquus  inferior  acts  most  strongly  to  prevent  downward 
vision.  The  direction  of  the  obliquns  inferior  does  not,  however, 
lie  exactly  in  the  plane  of  a  great  circle ;  it  therefore  not  only 
opposes  the  downward  rotation,  but  simultaneously  causes  a  rota- 
tion of  the  eye  about  the  axis  of  vision,  by  which  the  vertical 
meridian  is  abnormally  inclined  outward.  This  revolution  is  the 
greater  the  farther  vision  is  directed  toward  the  temporal  side. 
But  even  when  vision  is  directed  toward  the  median  plane  this 
pathological  inclination  of  the  meridian  persists,  since  in  this 
position  of  the  eye  the  rectus  inferior  contributes  in  causing  this 
same  rotation  about  the  axis  of  vision. 

For  the  objective  recognition  of  the  pathological  condition  it  is 
important  to  notice  that  the  eye  affected  falls  behind  when  vision 
is  directed  downward.  Since  in  the  median  direction  of  the  lines 
of  vision  the  rectus  inferior  acts  least  and  the  trochlearis  most  on 
the  downward  movement  of  the  cornea,  it  follows  that  the  conse- 
quence of,  for  instance,  a  paralysis  of  the  obliquus  superior  of  the 
right  eye  will  be  that  an  object  lying  to  the  left  and  downward 
can  be  properly  fixed  only  by  the  left  eye,  while  the  right  eye  falls 
behind  in  the  movement,  and  its  cornea,  relatively  to  the  fixed 
object,  stands  too  high.  Often,  however,  with  incomplete  paral- 
ysis of  the  trochlearis,  the  defect  in  movement  is  so  slight  that  it 
is  not  easy  to  recognize  it.  Upon  causing  the  patient  to  direct  his 
two  eyes  alternately  downward  and  inward,  it  will  be  seen  that 
when  the  aifected  eye  is  used  for  fixation  the  healthy  eye,  for  the 
reason  already  explained,  suffers  an  associated  deviation  down- 
ward. 

By  reason  of  the  relations  just  stated,  diplopia  appears  as  fol- 
lows. In  the  upper  half  of  the  field  there  is  single  vision.  Upon 
looking  downward,  homonymous  double  images  appear,  which  at 
the  same  time  are  projected  at  different  levels.  We  will  supjiose 
a  case  of  paralysis  of  the  trochlearis  on  the  right  side,  then  will 
the  image  of  the  right  eye  stand  the  lower,  and  the  distance  be- 
tween the  images  will  increase  on  looking  to  the  left,  while  it  ^vill 
decrease  on  looking  to  the  right.  At  the  same  time  it  is  noticed 
that  the  upper  ends  of  the  images  incline  toward  each  other.  It 
generally  appears  to  the  ]>atient  as  if  the  lower  image  were  the 


PARALYSIS    OF   THE   TROCHLEAEIS.  147 

nearer.  This  is  an  error  in  judging  of  distance,  which  certainly 
is  not  to  be  wondered  at,  since  its  proper  estimation  depends  essen- 
tially on  binocular  single  vision.  It  is  not  in  paralysis  of  the 
trochlearis  alone  that  the  lower  image  appears  the  nearer, — the 
same  thing  occurs  almost  invariably  in  all  forms  of  diplopia  in 
which  the  images  are  on  different  levels.  Forster*  first  explained 
this  optical  illusion  as  follows.  When  several  objects  lie  at  dif- 
ferent distances  but  in  the  same  horizontal  plane,  the  images 
from  the  nearer  objects  are  cast  upon  the  upper  part  of  the  retina. 
This  develops  the  habit  of  referring  images  in  the  upper  part  of 
the  retina  to  relatively  near  objects. 

The  most  important  diagnostic  points  are,  that  the  diplopia 
occurs  only  in  the  lower  half  of  the  field,  and  that  the  images  sepa- 
rate more  and  more  in  a  vertical  direction  as  vision  is  directed 
toward  the  median  plane.  In  some  cases  the  images  may  not  be 
homonymous,  but  slightly  crossed.  This  is  due  to  a  pre-existing 
elastic  preponderance  of  the  recti  externi  muscles,  which,  however, 
in  the  interest  of  binocular  single  vision,  is  overcome  by  a  stronger 
tension  of  the  interni.  If  under  these  circumstances  diplopia 
occur,  the  stimulus  to  a  strong  innervation  of  the  interni  muscles 
fails,  and  the  elastic  preponderance  of  the  externi  muscles  asserts 
itself.  The  disturbances  consist  i:n:-incipally  in  diplopia  when 
looking  downward.  This  is  especially  annoying  when  going  up- 
stairs. 

Finally,  we  must  consider  the  diife^ential  diagnosis  between 
paralysis  of  the  obliquus  superior  and  of  the  rectus  inferior.  In 
the  case  of  the  last,  downward  movement  is  limited,  and  there  is 
diplopia  in  the  lower  part  of  the  visual  field,  the  images  showing 
a  lateral  deviation  and  a  difference  of  height.  But  the  images  are 
crossed,  because,  since  the  downward  movement  is  now  effected 
by  the  trochlearis  alone,  the  cornea  is  at  the  same  time  directed 
outward.  The  difference  in  the  level  of  the  images  increases  as 
the  affected  eye  moves  outward.  Moreover,  the  images  are  in- 
clined in  the  opposite  direction,  being  wider  from  each  other  at 
the  top. 

The  etiology  and  treatment  are  the  same  as  in  the  other  ocular 
paralyses. 

*  Verhandlungen  der  Breslauer  medicin.  Section,  1859-60. 


148  SPASM   OF    THE    OCULAR   MUSCLES. 

SPASM    OF   THE   OCULAE   MUSCLES. 

Spasm  of  the  ocular  muscles  occurs  frequently  as  a  symptom  of 
cerebral  disease.  It  cannot  be  doubted  that  a  similar  condition 
may  also  occur  idiopathically.  Observations  on  this  subject  have, 
however,  been  few  and  not  decisive.  At  all  events,  it  may  be 
affirmed  that,  if  spasm  of  the  ocular  muscles  occurs  at  all  as  an 
idiopathic  disease,  it  is  only  very  exceptionally. 


STRABISMUS. 


Strabismus,  in  the  most  general  sense  of  the  word,  exists  when- 
ever the  visual  axes  do  not  intersect  at  the  point  fixed,  or  in  other 
words,  whenever  the  point  fixed  casts  its  image  upon  the  macula 
lutea  of  only  one  eye,  while  in  the  otlier  it  falls  upon  some  excen- 
tric  part  of  the  retina.  We  have  seen,  in  the  preceding  chapter, 
that  this  condition  occurs  as  a  constant  symptom  of  paralysis  of 
the  ocular  muscles,  and  we  have  frequently  used  the  expression 
"  paralytic  squint." 

It  follows,  from  the  law  of  the  symmetrical  innervation  of  both 
eyes,  that  in  paralytic  squint  the  degree  of  deviation  varies  greatly 
in  the  different  positions  of  the  eyes.  It  is  greatest  in  that  posi- 
tion where  the  greatest  demand  is  made  upon  the  paralyzed  muscle. 
Another  consequence  of  the  same  law  is  the  strong  secondary 
deviation  which  affects  the  healthy  eye,  whenever  the  affected  eye 
is  used  for  fixation  in  a  direction  in  which  a  demand  is  made  upon 
the  paralyzed  muscle. 

From  the  same  law  of  symmetrical  innervation  of  the  two  eyes, 
it  follows  that  in  typical  so-called  concomitant  squint  the  move- 
ments of  the  squinting  eye  accompany  those  of  the  normal  one, 
and  that  upon  using  the  affected  eye  for  fixation  the  associated 
deviation  of  the  eye  generally  used  for  fixation  is  equal  to  the 
usual  deviation  of  the  squinting  eye.  The  exceptions  to  this 
rule,  due  to  special  circumstances,  will  be  considered  later.  In 
general,  the  principle  just  stated  is  sufficient  to  distinguish  the 
paralytic  from  the  typical  squint. 

STRABISMUS   CONVERGENS. 

Donders  has  shown  that  in  the  great  majority  of  cases  strabis- 
mus convergens  exists  in  connection  with  hypermetropia.  The 
hypermetropia  is  often  manifest ;  but  even  when  convex  glasses  do 
not  improve  distant  vision,  even  when  the  patients  affirm  that 
they  do  not  see  at  a  distance  as  well  with  weak  convex  glasses  as 

149 


150  STRABISMUS   CONVEEGENS. 

with  the  naked  eye,  hypermetropia  is  not  absohitely  excluded. 
Frequently  there  is  associated  with  strabismus  convergens,  a  high 
degree  of  latent  tension  of  accommodation,  which'  yields  only  slowly 
under  the  energetic  use  of  atropine.  Donders'  investigations  also 
showed  that  not  the  highest  degrees  of  hypermetropia  oftenest 
induce  strabismus,  but  rather  the  medium  and  slight  degrees. 

The  physiological  ground  for  the  relation  between  hypermetropia 
and  strabismus  convergens  lies  in  the  very  nature  of  this  anomaly 
of  refraction.  It  is  known  that  for  distinct  vision  hypermetropic 
eyes  require  a  relatively  strong  tension  of  accommodation.  It  is 
further  known  that  a  physiological  connection  exists  between  the 
movement  of  convergence  and  accommodation, — that  is,  that  with 
the  increase  of  convergence  the  relative  range  of  accommodation 
approaches  the  eye.  It  is  accordingly  easy  to  understand  why,  in 
order  to  bring  the  relative  range  of  accommodation  nearer  to  the 
eye,  hypermetropes  should  converge  too  strongly.  While  they  are 
often  compelled  in  near  vision  to  exhaust  their  available  power  of 
accommodation,  and  to  work  with  the  relative  near  point,  they 
gain  by  a  relatively  too  strong  convergence  the  advantage  of 
bringing  the  entire  range  of  accommodation  nearer  the  eye.  They 
do  not  then  need,  when  working,  to  employ  their  entire  available 
accommodation,  but  only  a  small  part  of  it:  they  work  with  a 
relatively  small  tension  of  accommodation.  If  then  hyperme- 
tropia, from  its  very  nature,  can  induce  the  habit. of  associating 
each  action  of  accommodation  with  a  relatively  too  strong  con- 
vergence of  the  visual  axes,  the  question  arises,  why  all  hyperme- 
tropes do  not  squint.  It  is  plain  that  the  advantage  just  referred 
to,  of  working  with  a  relatively  slight  tension  of  accommodation, 
is  purchased  at  the  expense  of  binocular  vision.  Under  what 
circumstances  now  will  the  necessity  for  sparing  accommodation 
prevail,  and  when  will  binocular  single  vision  prevail?  In  the 
first  place,  there  will  be  but  slight  cause  for  sacrificing  binocular 
vision  when,  in  spite  of  relatively  too  strong  convergence,  no  dis- 
tinct retinal  images  are  obtained,  as  is  the  case  in  the  highest 
degrees  of  hypermetropia.  In  the  medium  and  lower  grades  of 
hypermetropia'  there  will  exist  the  inclination  to  exchange  binocu- 
lar single  vision  for  a  convenient  monocular  fixation  when  any 
cause  whatever  makes  binocular  fixation  less  valuable.  As  such 
causes,  differences  in  refraction,  or  in  the  acuity  of  vision  of  the 


STRABISMUS   CONVERGENS.  151 

two  eyes,  is  first  to  be  named.  It  was  explained  on  page  74  that 
wliere  tliere  is  difference  of  refraction  a  distinct  retinal  image  is 
formed  in  only  one  eye.  The  same  is  the  case  in  astigmatism, 
corneal  opacities,  etc.,  affecting  only  one  side.  But,  even  with 
faultless  retinal  images,  differences  in  the  acuteness  of  vision  will 
exert  the  same  effect  upon  binocular  vision.  In  this  connection 
is  especially  to  be  remembered  that  form  of  amblyopia  congenita 
which  occurs  oftener  associated  with  hypermetropia  than  with  any 
other  condition  of  refraction.  If  there  be  in  both  eyes  faultless 
and  distinctly  perceived  retinal  images,  the  incentive  to  unite 
them  binocularly  is  much  greater  than  when  there  is  an  ill-defined 
01"  indistinctly  perceived  retinal  image  in  one  eye  and  a  clear 
retinal  image  and  better  vision  in  the  other. 

Although  these  causes  for  convergent  squint,  as  pointed  out  by 
Donders,  often  enough  exist,  still,  it  must  be  remembered  that 
they  alone  do  not  necessarily  induce  it.  We  frequently  see  cases 
'of  bilateral  hypermetropia  with  considerable  differences  in  refrac- 
tion or  in  vision,  or  in  both,  without  there  being  any  squint,  and 
with  the  persistence  of  the  normal  binocular  visual  act. 

Other  favoring  circumstances  must  contribute  to  the  develop- 
ment of  strabismus  convergens.  Perhaps  it  is  in  this  respect 
not  without  influence,  that,  according  to  my  observations  at  least, 
in  a  very  considerable  number  of  these  cases  even  the  non-squint- 
ing eye  does  not  possess  full  sharpness  of  vision ;  this  induces  the 
effort  to  get  as  large  retinal  images  as  possible  by  approaching 
very  near  the  object,  which  in  turn  demands  strong  tension  of 
accommodation,  and  increases  the  tendency  to  convergence  of  the 
visual  axes.  All  influences  which  diminish  even  temporarily  the 
strength  of  the  muscle  of  accommodation  tend  in  the  same  direc- 
tion.  Contraction  of  the  range  of  accommodation  may,  not  only 
with  hypermetropia  but  even  Mith  emmetropia,  become  a  cause 
for  strabismus  convergens  in  young  persons.* 

There  are  still  other  causes  which  favor  convergence,  or  which 
render  it  difficult  to  maintain  parallelism  of  the  visual  axes.  In 
this  connection  Dondersf  has  shown  that  the  deviation  of  the  line 
of  vision  from  the  centre  of  the  cornea  is  not  only  generally  greater 


*  Bonders,  Het  tienjavig  bestaan,  etc.,  pag.  115. 
t  Arch.  f.  Opth.,  B.  ix.  1,  pag.  121. 


152  STRABISMUS   CX)NVERGENS. 

in  hypermetropia  than  in  emmetropia,  but  is  greater  in  hyperme- 
tropia  complicated  with  strabismus  convergens  than  in  the  same 
degree  of  hypermetropia  not  so  complicated.  The  more  the  line 
of  vision  deviates  inward,  the  more  the  cornea  must  diverge  when 
the  lines  of  vision  are  parallel,  and  we  have  seen  (p.  124)  that  the 
apparent  strabismus  divergens  of  hypermetropes  is  explained  by 
this  divergent  position  of  the  cornea.  A  greater  demand  is  made 
upon  the  recti  externi  in  maintaining  parallelism  of  the  visual 
axes  with  hypermetropia  than  with  either  emmetropia  or  myopia. 
This  is  the  reason  for  the  fact  mentioned  on  page  131,  that  in 
hypermetropia  only  a  slight  degree  of  divergence  of  the  visual 
axes  can  be  produced  by  prisms.  In  this  condition  of  refraction 
the  recti  externi  muscles  are  all  the  time  taxed  nearly  to  the  limit 
of  their  capacity.  The  subject  may  be  thus  formulated:  the  great 
deviation  of  the  lines  of  vision  from  the  corneal  centres,  in  hyper- 
metropia, causes  a  relative  insufficiency  of  the  recti  externi,  which 
favors  the  occurrence  of  strabismus  convergens. 

It  is  certain  also  that  in  many  cases  the  relations  of  muscular 
elasticity  induce  the  occurrence  of  strabismus.  This  is  seen  most 
plainly  in  cases  of  one-sided  blindness.  Frequently  the  blind  eye 
maintains,  at  least  at  first,  its  normal  position,  the  muscles  re- 
maining in  equilibrium  without  the  regulating  influence  of  binoc- 
ular single  vision.  If  squint  develop,  it  is  generally  strabismus 
divergens;  the  reasons  for  this  will  be  explained  later.  But  cases 
do  occur  in  which  the  blind  eye  acquires  a  pathological  conver- 
gence, which  indicates  a  pre-existing  preponderance  of  the  recti 
interni  muscles.  An  elastic  preponderance  of  the  recti  interni,  or 
what  amounts  to  the  same  thing,  an  insufficiency  of  the  recti  externi, 
may  be  overcome  just  as  may  the  hypermetropia  in  the  service  of 
binocular  single  vision ;  but  this  will  be  the  more  difficult  when 
both  causes  act  together,  and  the  strong  tension  of  the  interni 
may  induce  strabismus  convergens  when  acting  simultaneously 
with  causes  which  lessen  the  value  of  binocular  vision.  In  this 
way  strabismus  convergens  may  occur  as  well  with  emmetropia  as 
with  myopia.  Cases  in  which  strabismus  convergens  remains  after 
paralysis  of  the  abducens  belong  to  this  class. 

It  is  finally  to  be  mentioned  that  irritation  of  the  sensitive  oc- 
ular nerves  may  cause  reflex,  pathological  contraction  of  the  recti 
interni.     I  observed  this  unmistakably  in  the  case  of  a  child  two 


I 
I 


STRABISMUS   CONVERGENS.  153 

years  old,  Mhom  I  treated  with  nitrate  of  silver  for  purulent 
conjunctivitis.  After  each  application  to  the  conjunctiva  there 
occurred  a  strong  converging  squint,  which  disappeared  sponta- 
neously after  a  few  hours.  This  reflex  contraction  of  the  recti 
interni  may  explain  some  of  the  cases  in  which  corneal  opacities 
exist  in  connection  with  strabismus  convergens.  On  the  one  hand 
the  inflammatory  process,  which  leaves  the  opacity  behind  it,  may 
by  reflex  irritation  have  induced  the  strabismus  convergens ;  on 
the  other  hand,  however,  the  diminution  of  vision,  caused  by  the 
opacities,  acting  with  other  favoring  causes,  such  as  hypermetropia 
or  preponderance  of  the  recti  interni,  is  sufficient  to  produce  the 
strabismus. 

In  most  cases  strabismus  convergens  develops  in  early  child- 
hood, between  the  ages  of  two  and  seven  years.  It  is  possible 
that  it  occurs  congenitally.  There  is  no  doubt  that  the  conditions 
inducing  hypermetropia  and  abnormal  relations  of  elasticity  in 
the  ocular  muscles  are  hereditary. 

After  the  period  of  childhood  has  passed,  strabismus  convergens 
very  seldom  occurs.  It  may  happen  in  connection  with  myopia. 
Myopia  generally  causes  strabismus  divergens;  still,  it  may  some- 
times happen,  even  in  high  degrees  of  myopia,  that  the  lines  of 
vision  can  be  properly  converged  for  near  vision,  and  can  be  held 
in  that  position  without  straining.  This  may  be  due  to  a  more 
favorable  change  of  form.,  or  to  a  congenital  or  acquired  prepon- 
derance of  the  interni  recti  muscles.  This  happens  mostly  at  the 
expense  of  movement  outward,  which  is  always  more  or  less  lim- 
ited. This  limitation  may  become  such  that  it  is  impossible  to 
give  the  visual  lines  a  parallel  position  for  distant  vision.  Con- 
vergent squint  then  exists.  According  to  Von  Graefe,  the  occur- 
rence of  this  form  of  strabismus  convergens,  in  the  middle  grades 
of  myopia  (^  to  -^),  is  favored  by  continuous  work  with  strong  con- 
vergence of  the  visual  axes.  Under  these  circumstances  there  is 
developed  a  preponderance  of  the  recti  interni,  which  finally  cannot 
be  relaxed  sufliciently  to  admit  of  parallelism  of  the  visual  axes.* 

Strabismus  convergens,  as  a  consequence  of  paralysis  of  the 
abducens,  may  occur  at  any  time  of  life,  the  paralytic  strabismus 


*  Comp.  Donders,  Arch.  f.  Ophth.,  B.  ix.  1,  pag.  142,  and  Y.  Graefe,  Arch, 
f.  Ophth.,  B.  X.  1,  pag.  156. 

11 


1'54  STRABISMUS   CONVERGfeXS. 

gradually,  during  recovery  from  the  paralysis,  passing  into  con- 
comitant strabismus.  Diplopia  is  generally  present  in  all  cases 
of  strabismus  convergens  Avhicli  develop  later  than  childhood. 

The  most  frequent  form  of  strabismus  convergens  is  the  station- 
ary monolateral  squint.  One  and  the  same  eye  is  always  used  for 
fixation,  while  the  other  remains  turned  inward. 

We  have  before  said  that  in  general  the  angle  between  the 
visual  axis  of  the  squinting  eye  and  its  normal  direction  remains 
constant  as  well  during  associated  movements  as  during  the  sec- 
ondary squint,  which  affects  the  eye  usually  employed  for  fixation 
when  the  other  is  so  employed.  This  rule  must  not  be  regarded 
as  absolute ;  for  aside  from  certain  fluctuations  which  it  exhibits 
in  the  same  individual  within  short  periods  of  time,  it  generally 
increases  during  fixation  of  near  objects  and  Avhen  the  squinting 
eye  is  turned  outward.  The  mobility  of  the  eyes  does  not  by  any 
means  remain  unchanged  in  strabismus  convergens ;  as  a  rule,  the 
movement  outward  is  less  and  that  inward  greater  than  normal. 
This  limitation  of  movement  may  be  divided  symmetrically  be- 
tween the  two  eyes,  but  oftener  the  lateral  movement  of  the  squint- 
ing eye  is  noticeably  less  than  that  of  the  eye  used  for  fixation ; 
this  causes  an  increase  of  the  squinting  angle  when  looking  toward 
the  side  of  the  squinting  eye. 

Often,  too,  the  associated  deviation  occurring  upon  change  of 
fixation  is  observed  to  be  stronger  than  the  primary  squint.  Par- 
ticularly if  there  be  hypermetropia  on  both  sides,  but  with  differ- 
ence in  refraction,  the  squinting  angle  is  always  greater  when  the 
eye  with  the  higher  degree  of  hypermetropia  is  used  for  fixation 
than  when  the  other  is  used.  The  stronger  tension  of  accom- 
modation which  the  more  hypermetropic  eye  requires,  causes 
immediately  an  increase  of  convergence.  This  symptom  is  ^o 
characteristic  that  one  may  diagnose  from  it,  both  the  existence 
of  different  refraction  in  the  two  eyes  and  Avhich  eye  is  the  more 
hypermetropic,  even  when  the  hypermetropia  is  latent  in  both 
eyes. 

Alternating  strabismus  convergens  is  comparatively  rare.  Even 
when  vision  is  so  good  in  both  eyes  that  either  may  be  used  for 
fixation,  the  eyes  are  but  seldom  used  alternately.  Slight  differ- 
ences in  the  acuity  of  vision  generally  determine  the  habitual  use 
of  one  particular  eye. 


STRABISMUS    CONVERGENS.  155 

Periodic  strabismus  convergens  is  a  special  form  which  deserves 
mention.  Most  cases  of  squint  are  uot  permanent  from  the  be- 
ginning, but  become  so  after  a  short  time.  For  this  reason  only 
those  cases  are  called  periodic  squint  in  which  during  a  long 
period  the  squinting  appears  only  occasionally.  These  are  gener- 
ally cases  of  accommodative  squint  dependent  on  hypermetroj)ia. 
When  the  eyes  are  not  fixed  on  some  object  there  is  either  no 
apparent  or  only  a  slight  convergence;  it  becomes  considerable, 
however,  when  the  eifort  of  accommodation  is  made  in  order  to 
see  distinctly  a 'near  or  far  object. 

I  have  observed  in  emmetropic  eyes  another  form  of  periodic 
squint,  dependent  upon  an  elastic  preponderance  of  the  interni. 
Convergence  occurs  immediately  whenever  binocular  single  vision 
is  interrupted  by  prisms  refracting  vertically,  and  it  remains  a 
short  time  after  removal  of  the  prisms.  Squinting  followed  spon- 
taneously, generally  under  the  influence  of  some  slight  disturbance 
of  the  general  condition,  and  was  connected  with  diplopia. 

The  degree  of  strabismus  can  be  determined  exactly  only  by 
ophthalmoraetric  measurement,  but  for  the  purposes  of  practice  an 
approximative  estimate  is  sufficient. 

According  to  Von  Graefe,*  the  patient  is  directed  to  fix  an 
object  lying  in  the  median  plane  and  at  a  level  with  the  eye ;  a 
mark  is  then  made  on  the  under  lid  of  that  eye  exactly  below 
the  centre  of  the  cornea.  Then  the  symmetrical  point  under  the 
second  squinting  eye  is  determined,  as  well  as  the  point  upon  the 
lid  lying  directly  under  the  centre  of  the  deviating  cornea.  The 
distance  between  these  two  last-named  points  gives  the  linear 
measure  of  the  deviation  in  this  ])osition.  An  accurate  marking 
of  the  lid  is  in  practice  impossible,  on  account  of  the  movement 
caused  whenever  the  lid  is  touched,  and  the  difficulty  in  applying 
any  ink  or  coloring-matter  to  a  surface  covered  with  such  oily 
secretions.  One  must  content  himself  with  merely  noting  the 
point  in  question  on  the  first  lid,  and  compare  it  with  the  sym- 
metrical point  on  the  second  eye;  in  fact,  it  amounts  to  a  super- 
ficial estimation  of  the  linear  deviation. 

A  somewhat  more  exact  result  is  obtained  when  this  measure- 
ment is  made  by  the  help  of  a  scale,  used  in  the  following  manner. 


*  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  195. 


156  STRABISMUS   CONVERGENS. 

The  eye  generally  used  for  fixation  is  covered,  and  an  object  is 
fixed  with  the  squinting  eye ;  a  scale  divided  into  millimetres  is 
then  held  immediately  under  the  edge  of  the  lid,  and  it  is  noted 
what  division  of  the  scale  comes  immediately  under  the  centre  of 
the  pupil ;  the  other  eye  is  then  uncovered,  and  the  first  allowed 
to  resume  its  ordinary  squinting  position,  and  it  is  then  again 
noted  Mdiat  division  is  exactly  under  the  middle  of  the  pupil ;  in 
this  way  the  linear  measure  of  the  deviation  is  found.  The  sec- 
ondary deviation  of  the  other  eye  is,  of  course,  found  in  the  same 
manner.  If,  in  consequence  of  poor  vision,  the  squinting  eye 
cannot  be  steadily  fixed,  the  graduated  scale  may  be  held  in  such 
a  way  that  its  end  is  exactly  under  the  punctum  lachrymalis,  and 
while  fixation  remains  unchanged,  the  distance  between  that  point 
and  the  centre  of  the  pupil  is  determined,  first  for  the  normal  and 
tlien  for  the  squinting  eye.  The  difference  between  these  two 
measurements  is  the  linear  deviation.  Instead  of  the  ordinary 
millimetre  measure,  one  may  use  a  scale  made  of  ivory,  of  a 
shape  to  fit  the  lower  lid,  and  provided  with  a  handle.  The  scale 
is  so  graduated  on  its  free  edge  that  0  is  at  the  middle,  and  the 
millimetres  are  counted  from  that  point  in  both  directions.*  An- 
other "  strabometer"t  consists  of  two  small  scales,  one  for  each 
eye,  fitting  closely  to  the  under  lid,  each  provided  with  a  movable 
indicator,  and  both  fastened  on  the  same  handle.  By  means  of 
a  screw  the  indicators  may  be  adjusted  on  either  side  to  the  point 
exactly  under  the  centre  of  the  pupil. 

It  is  advisable  in  every  case  to  make  this  measurement,  even 
though  it  cannot  be  done  with  strict  accuracy.  It  is  to  be  re- 
membered that  for  the  purposes  of  operative  treatment  the  exact 
measurement  of  the  deviation  is  not  so  important  as  was  formerly 
thought. 

Often  the  squinting  eye  turns  upward  as  well  as  inward;  in 
such  a  case,  upon  changing  fixation  the  eye  generally  used  turns 
usually  upward,  seldom  downward.  Where  there  is  vertical 
deviation  it  generally  persists  after  change  of  fixation.  I  have 
often  observed  a  rotation  of  the  eye  in  connection  with  these  dif- 
ferences in  level ;    generally,  simultaneously  with  the  deviation 

*  Laurence,  The  Optical  Defects  of  the  Eye. 

•f  Eduard  Meyer,  Du  Strabisme  et  de  la  Strabotomie,  Paris,  1863. 


STRABISMUS  CONVERGENS.  157 

upward  there  is  an  inclination  outward  of  the  vertical  meridian, 
and  inversely,  upon  returning  to  fixation,  it  inclines  inward.  Gen- 
erally the  other  eye  rolls  in  a  corresponding  manner,  that  is,  the 
meridians  of  both  eyes  incline  simultaneously  either  to  the  right 
or  to  the  left,  but  they  do  not  always  stand  at  the  same  level. 

Typical  concomitant  squint  is  very  seldom  accompanied  by 
diplopia.  So  long  as  the  theory  of  an  anatomically  preformed 
and  uniformly  acting  symmetrical  correspondence  of  the  retinae 
was  entertained,  this  fact  could  be  explained  only  upon  one  of 
two  assumptions, — either  that  in  consequence  of  asymmetry  of  the 
retinas,  in  spite  of  the  strabismus,  a  binocular  union  of  the  two 
fields  of  vision  takes  place,  or  that  the  retinal  image  in  the  squint- 
ing eye  is  excluded  from  perception  by  some  psychical  process,  or, 
as  is  generally  said,  "is  suppressed."  Now,  there  cannot  be  an 
asymmetry  of  the  retinae  in  the  sense  above  indicated ;  if  there 
were,  diplopia  would  always  occur  when  a  proper  direction  is  given 
to  the  lines  of  vision  by  an  operation,  but  it  is  well  known  that 
such  is  not  the  case.  For  this  reason  the  other  view,  which  as- 
sumes a  suppression  of  the  retinal  images,  has  been  generallv 
accepted,  since  it  seems  to  relieve  the  subject  of  all  difiiculty. 

It  was  thought  that  when  the  attention  was  concentrated  upon 
the  central  image  in  the  eye  used  for  fixation,  the  ease  with  which 
the  image  in  the  squinting  eye  could  be  suppressed,  depended  upon 
its  eccentricity,  that  is,  its  position  on  a  less  sensitive  part  of 
the  retina.  But  in  paralytic  squint  exactly  these  conditions  do 
not  prevent  the  occurrence  of  diplopia. 

But  supposing  the  double  vision  of  one  and  the  same  object 
may  be  avoided  by  a  considerable  eccentricity  of  one  of  the 
retinal  images,  what  becomes  then  of  the  image  which  is  cast 
upon  the  macula  lutea  of  the  squinting  eye  ?  According  to  the 
theory  of  corresponding  points,  the  images  at  both  retinal  centres 
are  projected  upon  each  other  in  space,  from  which  would  result 
about  as  much  trouble  as  from  diplopia. 

A  careful  analysis  of  binocular  vision  with  strabismus,  shows 
that  the  hypothesis  of  the  suppression  of  the  retinal  image  in  the 
squinting  eye  does  not  sufficiently  explain  all  the  facts. 

The  well-known  fact  that  the  squinting  eye  contributes  toward 
widening  the  field  of  vision,  compels  the  admission  that  its  func- 
tion is  not  absolutely  suspended.     Accordingly,  a  participation  in 


k 


158  STRABISMUS   CO]S'VEEGENS. 

the  act  of  vision  must  be  admitted  for  the  median  part  of  the 
retina,  which  serves  for  eccentric  vision  outward,  but  it  was 
thought  that  the  theory  of  the  suppression  of  retinal  impressions 
could  still  be  retained  Avith  reference  to  the  other  parts  of  the 
retina.  One  can,  however,-  easily  satisfy  himself  that  even  that 
jiart  of  the  field  of  vision  of  the  squinting  eye  which  coincides 
with  that  of  the  eye  used  for  fixation  is  not  excluded.  Of  course 
it  is  only  cases  in  which  the  squinting  eye  has  moderately  good 
vision  which  can  be  the  subjects  of  such  experiments. 

The  following  experiment  is  very  simple.  The  patient  directs 
the  eye  generally  used  for  fixation  upon  an  object  in  the  median 
plane,  and  on  the  same  level  with  itself;  a  small  mirror,  or,  still 
better,  a  transparent,  reflecting  ])lane  glass,  is  then  placed  before 
the  squinting  eye,  its  edge  supported  on  the  nose,  and  its  surface 
so  held  that  objects  behind  the  patient  are  reflected  in  it,  A  light 
is  best  used  for  this  purpose  which  is  placed  behind  and  to  the 
side  of  the  head,  and  at  a  level  with  the  eye.  Patients  with  a 
little  skill  soon  learn  to  receive  the  imao-e  of  the  light  with  the 
squinting  eye,  and  to  throw  it  at  will  upon  any  part  of  the  retina. 
It  can  be  proved  in  this  way  that  in  binocular  vision  there  is 
consciousness  of  tiie  retinal  impressions  made  in  the  squinting 
eye.  Now,  if  the  retinal  images  of  the  squinting  eye  are  not 
suppressed,  but  are  perceived  in  about  the  same  way  as  are  ob- 
jects in  the  periphery  of  tlie  field  of  vision,  the  relations  of  the 
two  retinae  cannot  be  the  same  as  in  the  normal  condition.  In 
fact,  the  relations  are  so  complicated  that  it  is  difficult  to  formu- 
late them.  At  all  events,  the  facts  above  stated  cannot  be  ex- 
plained upon  the  theory  of  a  preformed  and  therefore  unchanging 
symmetrical  correspondence  of  the  retinre. 

If  now  we  find,  on  the  other  hand,  that  diplopia,  such  as  we 
can  provoke  during  the  normal  binocular  visual  act,  and  as  it 
occurs  in  cases  of  paralysis  of  the  ocular  muscles,  agrees  fully 
with  the  theory  of  retinal  symmetrical  correspondence,  all  the 
facts  may  be  reconciled  by  assuming  that  the  relations  of  the 
corresponding  retinal  parts  are  not  congenital  but  acquired. 

We  bring  the  macula  lutea  exactly  opposite  those  objects  upon 
which  the  attention  is  directed,  as  a  consequence  of  that  physio- 
logical preference,  in  respect  of  acuteness  of  vision,  which  has 
made  this  place  the  centre  of  the  retina ;  and  that  we  see  singly 


I 


STRABISMUS    CONVERGENS.  159 

an  object  fixed  with  both  retinal  centres  must  be  regarded  as  a 
habit  acquired  from  experience.  When  binocular  fixation  is  once 
established,  then  the  symmetrical  points  of  the  retinee  first  ac- 
quire the  significance  of  correspondence.  If  now,  for  any  of  the 
reasons  above  stated,  binocular  fixation  be  relinquished  in  early 
childhood,  no  habit  is  developed  of  uniting  the  two  retinal  images, 
but  each  eye  projects  its  field  of  vision  in  the  proper  manner. 
Each  eye  for  itself  sees  the  objects  in  the  direction  toward  which 
it  is  turned.  Diplopia  does  not  occur  in  these  cases  because  that 
depends  upon  a  previous  habit  of  uniting  the  two  fields  of  vision. 
If  a  binocular  union  of  the  two  retinal  images  never  occurs,  then 
there  will  be  no  diplopia  when  the  field  of  vision  of  one  eye  is 
moved  up  or  down  by  a  prism  refracting  vertically,  and  such  is 
the  fact  in  many  cases  of  strabismus. 

There  is  not  always  the  absolute  impossibility  of  perceiving 
double  images.  Often  an  inconsiderable  remainder  of  binocular 
sino-le  vision  is  retained.  In  such  cases  double  imasres  do  not 
occur  spontaneously,  but  they  may  be  made  perceptible  by  means 
of  a  colored  glass  and  a  vertically  refracting  prism.  Nevertheless, 
the  results  are  very  inconstant;  the  double  images  appear  and 
disappear  again  without  the  patient  being  able  every  time  to 
perceive  them  with  certainty.  Their  positions  do  not  generally 
agree  with  the  theory  of  the  correspondence  of  symmetrical  points. 
For  instance,  they  show  only  slight  horizontal  separation,  in  spite 
of  considerable  convergence,  or  they  are  crossed  when  they  should 
be  homonymous,  or  the  double  images  may  always  stand  one 
above  the  other,  and  never  side  by  side.  It  sometimes  happens 
that,  with  the  help  of  a  red  glass  before  one  eye  and  a  vertically 
refracting  prism  before  the  other,  double  images  are  seen ;  but 
when  by  a  slow  revolution  of  the  prism  the  vertical  distance 
between  the  double  images  is  decreased,  they  suddenly  disappear, 
even  before  the  refracting  angle  has  revolved  through  45°,  and 
they  cannot  be  again  called  up. 

For  many  cases  the  stereoscope  is  an  excellent  instrument  for 
examining  the  relations  of  binocular  vision  in  squint.  Du  Bois- 
Reymond*  first  called  attention  to  this.     Shortly  after  the  dis- 


*  Ueber  eine  orthopadische  Ileilmethode  des  Schieleiis,  Arch.  f.  Anat.  u. 
Physiol.,  1852,  pag.  541. 


160  STRABISMUS   CONVERGENS. 

coveiy  of  the  instrument,  he  made  the  remark  that  for  an  ortho- 
pedic treatment  of  squint,  no  plan  promised  more  than  that  of 
methodical  practice  with  the  stereoscope.  Javal*  arrived  later  at 
the  same  opinion. 

The  stereoscope  presents  the  advantage  that  each  eye  has  its 
own  separate  field  of  vision,  into  which  suitable  objects  may  be 
introduced.  The  only  difficulty  is,  that  in  many  cases  the  patient 
is  not  able  to  see  in  the  stereoscope  the  two  fields  of  vision  at  the 
same  time,  but  always  perceives  only  that  of  the  eye  used  for 
fixation.  This  may  be  regarded  as  a  "suppression"  of  the  retinal 
image  in  the  squinting  eye;  but  it  is  remarkable  that  the  retinal 
image  of  the  normal  eye  can  be  suppressed  with  the  same  readi- 
ness so  soon  as  the  generally  squinting  eye  is  used  for  fixation. 
But  another  interpretation  of  this  phenomenon  is  possible.  One 
who  is  generally  accustomed  to  binocular  fixation  will  endeavor 
to  fix  binocularly  in  the  stereoscope,  but  the  squinting  patient, 
accustomed  to  monocular  fixation,  will  endeavor  to  fix  monocu- 
larly  in  the  stereoscope.  Tiie  entire  retina  of  the  squinting  eye 
serves  in  this  case  only  for  eccentric  vision,  and  just  such  stereo- 
scopic experiments  are  well  calculated  to  demonsti-ate  how  difficult 
it  is  to  perceive  distinctly  eccentric  retinal  images  even  with  the 
normal  visual  act. 

In  other  cases,  after  some  effi^rt,  the  patient  succeeds  in  seeing 
the  two  stereoscopic  fields  of  vision  simultaneously;  when  this  is 
accomplished,  he  may  proceed  to  practice  in  uniting  the  t\vo  retinal 
images.  For  this  purpose,  Javal  proposes  to  place  in  each  of  the 
two  stereoscopic  fields  of  vision,  a  wafer  contrasting  in  color  with 
the  background.  The  distance  between  the  two  wafers  corre- 
sponds to  the  distance  between  the  lines  of  vision  where  they  pierce 
the  fields.  In  order  to  know  from  the  statements  of  the  patient 
whether  binocular  union  or  only  monocular  vision  takes  place,  a 
wafer  of  another  color  is  placed  above  one  of  the  first  wafers  and 
another  below  the  other.  In  the  binocular  image  there  must 
appear  to  be  three  wafers  one  above  the  other. 

One  must  be  very  careful  in  drawing  conclusions  from  the 
statements  of  the  patients.  Even  when  the  three  wafers  are  seen 
to'  stand  perpendicularly  over  each  other,  there  need  be  no  binoc- 

*  Klin.  Monatsbl.  fiir  Augenheilk.,  1864,  pag.  404. 


STRABISMUS   CONVEEGENS.  161 

ular  fixation  of  the  two  middle  wafers  intended  for  binocular 
union.  In  spite  of  an  abnormal  direction  of  the  axis  of  the 
squinting  eye,  the  images  may  appear  perpendicularly,  one  above 
the  other,  just  as  in  squint  double  images  standing  one  above  the 
other  may  be  provoked  by  prisms  refracting  vertically.  On  the 
other  hand,  it  may  happen  that  after  an  operation  has  established 
a  normal  direction  of  the  visual  axes,  the  three  wafers  may  be  seen 
one  above  the  other,  and  still  the  middle  one  not  be  a  binocular 
image.  This  can  be  detected  by  marking  one  wafer  with  a  hori- 
zontal and  the  other  with  a  vertical  line ;  the  binocular  image 
would  then  appear  as  if  marked  Avith  a  cross ;  but,  although  all 
the  wafers  appeared  to  stand  vertically  over  each  other,  the  middle 
one  in  these  cases  was  generally  marked  with  either  a  horizontal 
or  a  vertical  line,  and  the  binocular  image,  marked  with  a  cross, 
appeared  during  the  experiments  only  momentarily  or  not  at  all. 

In  the  great  majority  of  squinting  patients  the  normal  relations 
between  the  two  retinal  images  do  not  exist. 

Generally  they  see  with  both  eyes  at  the  same  time,  but,  so  to 
speak,  monocularly.  In  many  cases  a  new  relation  of  correspond- 
ence appears  to  develop  between  the  macula  lutea  of  the  eye  used 
for  fixation  and  that  retinal  region  in  the  squinting  eye  on  which 
the  image  of  the  object  fixed  is  usually  cast ;  and  finally  it  may 
happen,  especially  in  those  cases  of  squint  which  develop  at  a  later 
period  of  life,  that  double  images  appear  in  a  manner  very  annoy- 
ing to  the  patients;  this  is,  however,  by  no  means  always  the 
case.  For  instance,  in  the  relative  strabismus  divergens  of  my- 
opes, it  may  happen  that  distant  objects  are  properly  fixed  by  a 
normal  visual  act;  double  images  may  be  easily  provoked  by 
prisms,  and  are  united  in  the  physiological  manner,  and  never- 
theless it  is  in  many  of  these  cases  impossible  to  provoke  double 
images  for  near  objects,  although  there  is  evident  divergence  of 
the  visual  axes  when  they  are  fixed.  We  see  in  these  cases  the 
normal  binocular  visual  act  associated  with  a  normal  direction  of 
the  visual  lines,  but  with  an  abnormal  position  of  the  eyes  the 
relations  of  binocular  vision  assume  an  abnormal  character  also. 

AVe  have  already  learned  that  defective  vision  of  one  eye  favors 
the  occurrence  of  squint;  it  would  be  reasoning  in  a  circle  to 
argue  from  the  fact  that  a  considerable  number  of  squinting  eyes 
are  amblyopic,  that  consequently  squint  is  the  cause  of  amblyopia. 


162  STRABISMUS    CONVERGENS. 

So  long  as  the  theory  was  entertained  that  the  retinal  impressions 
in  the  sqninting  eye,  in  order  not  to  cause  diplopia,  were  forcibly 
suppressed  by  a  kind  of  psychical  process,  it  was  but  one  step 
further  to  conclude  that  in  this  way  the  power  of  vision  in  the 
squinting  eye  diminished  ;  that  is,  in  consequence  of  the  sup- 
pression of  the  physiological  retinal  excitation  the  excitability 
itself  finally  became  blunted.  So  soon  as  we  declare  that  tlieory 
to  be  insufficient,  we  must  examine  more  carefully  the  effect  of 
strabismus  in  the  deviating  eye. 

In  the  first  place,  it  is  to  be  remarked  that  cases  occur  in  which, 
with  strong  monolateral  squint,  double  images  neither  exist  nor 
can  be  provoked,  but  that  nevertheless  the  squinting  eye  possesses 
good  vision.  The  theory  that  amblyopia  with  strabismus  is  caused 
by  the  suppression  of  the  retinal  impressions  is  not  supported  by 
these  cases. 

Secondly,  there  are  no  observations  which  prove  that  an  eye 
which  once  possessed  good  vision  has  become  amblyopic  in  conse- 
quence of  strabismus. 

Thirdly,  attention  has  been  called  to  the  nature  of  the  aml)lyoj)ia, 
particularly  to  a  certain  group  of  cases  in  which  central  vision  is 
more  or  less  diminished,  while  the  rest  of  the  field  is  unatfected. 
In  cases  showing  the  highest  degree  of  this  form  of  amblyopia, 
central  vision  is  so  weak  that  an  eccentric  part  of  the  retina,  on 
the  nasal  side,  possesses  better  vision  than  the  macula  lutea.  In 
consequence  of  this,  such  objects  as  can  still  be  seen,  are  fixed  by 
turning  the  visual  axis  inward ;  eccentric  fixation  inward  takes 
place.  The  amblyopia,  under  these  circumstances,  is  generally  so 
great  that  fingers  can  be  counted  only  at  the  distance  of  a  few 
feet.  No  changes  can  be  observed  by  the  ophthalmoscope.  Par- 
ticularly the  optic  nerve  and  retina  appear  to  be  in  every  respect 
normal.  This  is  certainly  a  well-marked  form  of  amblyopia,  but 
it  is  absolutely  identical  with  that  frequent  form  of  amblyopia 
congenita  which,  in  extreme  cases,  is  generally  unilateral,  and 
Avhich  often  occurs  in  eyes  which  do  not  squint. 

Only  one  circumstance  remains  which  would  seem  to  indicate 
that  squint  exercises  an  injurious  influence  upon  the  vision  of  the 
eye  affected.  In  a  certain  class  of  cases  the  vision  is  improved  by 
the  separate  practice  of  the  squinting  eye.  In  reference  to  this 
fact,  we  should  first  examine  whether  the  defect  of  vision  in  these 


STRABISMUS   CONVERGENS.  163 

cases  depends  upon  amblyopia  or  some  other  cause;  for  an  eye 
possessing  normal  sensitiveness  of  the  retina  may  still  not  be  able 
to  see  distinctly;  for  instance,  in  case  of  hypermetropia  with 
paralysis  of  the  accommodation.  For  each  individual  case  it 
is,  of  course,  of  diagnostic  and  prognostic  importance  to  decide 
whether  the  defect  in  vision  depends  upon  amblyopia  congenita 
or  some  other  cause.  In  a  series  of  such  cases,  in  spite  of  normal 
distinctness  of  vision,  there  is  nevertheless  such  functional  in- 
ability of  the  squinting  eye  that,  for  instance,  after  reading  a  few 
lines,  the  letters  lose  their  sharpness  and  become  confused ;  pain 
is  soon  felt  in  the  eye,  so  as  to  make  reading  impossible.  That 
weakness  of  the  accommodation  is  one  of  the  elements  in  this  con- 
dition is  shown  by  the  fact  that,  generally,  vision  is  better  with 
convex  glasses  than  with  the  naked  eye ;  but  this  explanation  is 
not  sufficient,  since  even  with  convex  glasses  fatigue  is  soon  ex- 
perienced. We  must  therefore  conclude  that  these  cases  consist 
essentially  in  a  rapid  exhaustion  of  the  functional  power  of  the 
retina.  '  Most  of  the  patients  are  perfectly  conscious  of  the  inability 
of  the  squinting  eye;  they  affirm  that  they  cannot  see  anything 
with  it;  they  read,  for  instance,  some  words  from  No.  16  or  14  of 
Jaeger's  test  letters,  and  then  put  the  book  aside,  fatigued.  If  one 
insist,  however,  that  they  shall  continue  the  experiment,  they  read 
still  further,  with  the  same  difficulty  perhaps,  No.  8  or  6,  or  even 
No.  4  or  No.  3.  The  extract  of  Calabar  bean  is  generally  of 
more  assistance  to  them  than  convex  glasses. 

The  rule  may  be  now  laid  doAvn  that  the  degree  of  vision  ap- 
parent upon  making  the  first  experiment  can  be  best  improved  by 
the  use  of  Calabar  extract,  by  separate  practice  and  persistent  use 
of  the  squinting  eye.  And  though  this  practice  does  not  succeed 
in  all  cases,  still,  the  good  influence  exercised  by  separate  practice 
has  been  sufficiently  shown.  The  evil  influence  of  squint  depends 
not  so  much  upon  the  diminution  of  the  acuteness  of  vision  as 
upon  functional  incapacity  of  the  retina,  affecting  it  just  as  other 
organs  are  affected  by  the  want  of  exercise.  The  entire  attention 
of  the  squinting  patient  is  concentrated  upon  the  eye  used  for  fixa- 
tion, often  so  intensely  that  it  is  very  difficult  for  him  to  divide  his 
attention  upon  his  two  eyes  and  perceive  the  retinal  images  in  the 
squinting  one.  For  these  cases  physiological  analogies  are  not 
wanting  ;  many  retinal  images  move  across  the  peripheral  parts  of 


164  STRABISMUS   CONVEEGENS. 

our  retina  without  our  seeing  them.  The  entire  retina  of  the 
squinting  eye,  including  its  macula  lutea,  serves  only  for  eccentric 
vision,  since  every  object  in  the  periphery  of  the  visual  field  to 
which  the  attention  is  called  is  fixed  with  the  normal  eye.  There 
is,  in  fact,  neglect  on  the  part  of  the  squinting  eye,  and  particu- 
larly of  its  macula  lutea,  which  does  not  get  the  necessary  exer- 
cise. Its  retinal  images  have  the  same  claim  for  recognition  as 
those  of  the  macula  lutea  of  the  fixing  eye,  and  still  the  attention 
is  not  directed  to  them  any  more  than  to  any  peripheral  retinal 
image.  The  consequence  of  this  insufficient  practice  appears  to 
be  not  so  much  loss  of  distinct  vision  as  of  the  ability  to  main- 
tain vision  continuously. 

We  often  hear  it  asserted  by  persons  in  whom  no  abnormal 
position  of  the  eyes  is  perceptible,  that  their  former  squint  has 
disappeared  spontaneously.  Aside  from  such  cases  as  depend 
upon  paralysis  of  the  ocular  muscles,  it  is  not  improbable  that  even 
typical  concomitant  squint  may  disappear  spontaneously  ;  at  least, 
I  have  been  able,  in  the  cases  of  several  persons  who  have  made 
such  assertions,  to  detect  both  defective  vision  in  the  eye  ibrmerly 
said  to  squint  and  an  absence  of  the  binocular  visual  act.  Such 
cases  are  rare,  and  the  conditions  under  which  this  spontaneous 
recovery  occurs  are  not  known. 

The  influence  exerted  by  hy})ermetropia  upon  the  develoj^ment 
of  squint  suggested  the  idea  that  the  correction  of  this  anomaly 
of  refraction  might  prevent,  or  might  even  relieve  a  squint  when 
once  established.  And,  in  fact,  one  often  has  the  opportunity  to 
demonstrate  the  favorable  influence  which  correction  of  hyperme- 
tropia  exerts  upon  incipient  strabismus  convergens.  Generally, 
however,  the  extreme  youth  of  the  patients  renders  this  treatment 
unavailable.  In  children  between  the  ages  of  two  and  seven  years 
it  is  generally  possible  to  demonstrate  the  existence  of  iiyperrae- 
tropia  only  by  ophthalmoscopic  examination,  and  even  this  presents 
its  difficulties. 

But  to  correct  fully  the  hypermetropia  and  to  cause  spectacles 
to  be  worn  is  at  this  age  impracticable  and  indeed  dangerous. 
How  likely  such  a  child  is  to  fall  and  wound  itself  seriously 
with  the  splinters  of  the  broken  glasses !  With  older  children, 
who  can  be  trusted  with  spectacles,  the  time  is  generally  past  for 
any  hope  of  influencing  the  strabismus  by  correcting  the  hyper- 


STEABISMUS   DIVERGENS.  165 

metropia.  The  rectus  internus  is  already  shortened  and  the  ex- 
tern us  lengthened.  That  actual  structural  changes  have  occurred 
in  the  muscles  implicated  is  evident  during  the  operation  for 
squint.  This  is  perceived,  upon  cutting  through  the  shortened 
muscle,  by  the  resistance  it  offers  and  the  way  it  creaks  under  the 
scissors,  while  on  bringing  forward  its  antagonist  one  can  see  that 
it  is  very  weakly  developed. 

Although  as  a  rule  the  operative  treatment  is  the  only  effectual 
one,  we  ought  in  every  case  before  resorting  to  it  to  do  all  that  we 
can  to  improve  binocular  and  monocular  vision. 

It  has  been  mentioned  that  the  usefulness  of  the  squinting  eye 
may,  in  many  cases,  be  increased  by  separate  practice,  assisted  Avhen 
necessary  by  convex  glasses  or  Calabar  extract.  In  some  rare 
cases  it  is  even  possible  to  restore  the  lost  binocular  vision.  These 
results  are,  however,  attained  only  by  long  practice,  and  are  not  to 
be  expected  as  the  immediate  consequences  of  an  operation. 

STEABISMUS    DIVERGENS. 

Strabismus  divergens  is  caused,  as  is  strabismus  convergens, 
sometimes  by  anomalies  of  the  muscles  and  sometimes  by  the 
condition  of  refraction. 

Many  cases  of  the  most  extreme  divergence  are  caused  simply 
by  an  elastic  preponderance  of  the  externi.  At  first  the  visual 
axes  can  be  converged,  but  the  necessary  tension  cannot  long  be 
sustained,  and  while  one  eye  remains  fixed  the  other  deviates  out- 
ward. Most  patients  in  this  condition  relinquish  binocular  fixa- 
tion for  near  objects.  Convergence  is  soon  entirely  forgotten  ;  even 
parallelism  of  the  visual  lines  is  attained  with  difficulty  ;  in  place 
of  accommodative  movements  only  associated  ones  are  made,  and 
the  insufficiency  of  the  interni  muscles  finally  becomes  so  great 
that  even  in  associated  movement  inward,  the  squinting  eye  falls 
behind  the  other. 

In  many  cases  the  gradual  dev^elopment  of  this  insufficiency  of 
the  interni  muscles  is  due  to  some  peculiarity  of  the  visual  act. 
Among  these  are  those  cases  in  which  strabismus  divergens  occurs 
in  consequence  of  blindness  on  one  side.  At  first  the  movements 
of  the  eyes  appear  normal ;  gradually,  during  near  vision,  the 
convergence  becomes  insufficient;  later,  the  blind  eye  makes 
associated  instead  of  accommodative  movements ; ''the  recti  interni 


166  STRABISMUS   DIVERGENS. 

are  not  sufficiently  exercised,  and  no  longer  counterbalance  the  recti 
extern i.     Finally  there  comes  to  be  divergence  in  every  position. 

A  similar  process  may  be  developed  when  there  is  good  vision 
on  both  sides,  but  with  emmetropia  in  one  eye  and  a  higli  degree 
of  myopia  in  the  other.  Generally,  under  these  circumstances,  the 
myopic  eye  is  used  for  near  vision,  since  without  accommodation  it 
receives  larger  retinal  images  than  the  emmetropic  one,  which  in 
its  turn  is  used  only  for  distant  vision.  The  absence  of  accommo- 
dation during  near  vision  is  sufficient  to  give  to  the  emmetropic 
eye  a  relatively  divergent  position.  In  such  a  case  annoying 
diplopia  does  not  generally  exist,  because  the  attention  is  directed 
exclusively  upon  the  sharp  retinal  image  in  the  myopic  eye,  the 
blurred  image  in  the  emmetropic  one  being  neglected.  For  dis- 
tant vision  the  relations  are  reversed;  here  the  image  in  the 
myopic  eye  is  neglected,  and  the  attention  is  directed  exclusively 
upon  that  in  the  emmetropic  eye.  This  strictly  separate  use  of 
the  two  eyes  excludes  the  exercise  of  accommodation  and  of  con- 
vergence. The  emmetropic  eye  experiences  generally  a  diminution 
in  its  range  of  accommodation,  while  the  circumstance,  that  in 
near  vision,  associated  instead  of  accommodative  movement  takes 
place,  leads  to  a  relative  preponderance  of  the  recti  externi  and 
to  strabismus  divergens. 

With  unilateral  myopia  of  a  slight  degree,  the  maintenance  of 
the  normal  visual  act  is  quite  possible. 

The  influence  of  the  condition  of  refraction  in  causing  strabis- 
mus divergens  becomes  apparent  when  one  includes  in  his  inves- 
tigations all  those  cases  of  relative  divergence  in  which  during 
distant  vision  there  is  no  abnormal  position,  but  insufficient  con- 
vergence during  near  vision.  In  at  least  ninety  per  cent,  of  these 
cases  myopia  exfsts.  The  connection  between  the  two  conditions 
depends  upon  the  change  of  form,  and  the  peculiarity  of  movement 
due  to  it,  in  myopic  eyes. 

In  his  investigations  on  this  subject,  Schuurmann*  arrived  at  the 
following  results  with  reference  to  the  movements  of  myopic  eyes. 
Movements  in  the  horizontal  plane,  as  Donders  and  Doyerf  had 
already  found,  are  less  in  myopia  than  in  emmetropia.  As  a  rule, 
movement  decreases  as  the  myopia  increases.     Moreover,  myopic 

*  Vijfde  Yerslag,  etc.,  1864.  '    f  Donders,  1.  c,  pag.  159. 


STRABISMUS    DIVEEGENS.  167 

as  well  as  emmetropic  eyes  show  a  decrease  of  movement  de- 
pendent upon  advancing  age.  The  relation  between  inM'ard  and 
outward  movement,  relatively  to  the  line  of  vision,  is  the  same  in 
myopia  as  in  emmetropia, — that  is,  the  movement  inward  is  gener- 
ally greater  than  the  movement  outward.  The  degree  of  conver- 
gence attainable  by  different  myopes  varies  greatly.  The  maxi- 
mum of  convergence  is  greater  than  normal  Avith  some  myopes, 
and  less  with  others.  The  divergence  to  be  produced  by  prisms 
is  on  an  average  greater  in  myopia  than  in  emmetropia,  for  which 
reason,  as  remarked  on  page  131,  in  spite  of  less  deviation  of  the 
visual  lines  from  the  centres  of  the  corneas,  they  can,  neverthe- 
less, be  directed  farther  outward  than  in  emmetropia, — that  is, 
greater  divergence  can  be  attained. 

The  movenients  of  myopic  eyes  are  restricted,  because  in 
myopia  all  the  diameters  of  the  eye,  but  especially  the  sagittal 
diameter,  are  increased.  The  ellipsoidal  form  which  the  eye 
thereby  acquires  prevents  its  j^laying,  as  before,  like  a  ball  in  the 
capsule  of  Tenon.  Movement  becomes  possible  only  with  a 
simultaneous  displacement  of  the  orbital  tissues,  which,  of  course, 
present  a  resistance  not  met  with  when  the  eye  more  nearly 
approaches  the  form  of  a  sphere. 

The  defect  in  associated  ocular  movements  can  be  compensated 
for  by  movements  of  the  head,  but  no  such  substitution  can  be 
made  for  insufficient  convergence.  Divergence  is  the  more  likely 
to  occur,  for  the  reason  that  the  change  in  the  form  of  the  eye 
causes  greater  resistance  on  the  part  of  the  external  muscles. 

Myopic  eyes  generally  appear  more  prominent  than  emmetropic 
ones.  The  elongation  of  the  axes  appears  to  cause  a  displace- 
ment forward.  Since  the  distance  between  the  margin  of  the 
cornea  and  the  insertion  of  the  muscles  is  not  changed,  the  in- 
crease in  the  volume  of  the  eye  must  cause  increased  tension  of 
the  recti  muscles.  The  rectus  externus  is  the  muscle  which  ex- 
periences this  tension  most.  While  the  expansion  of  the  eye 
displaces  the  insertion  of  the  rectus  internus  only  forward,  that  of 
the  rectus  externus  is  displaced  outward  as  well  as  forward.  On 
account  of  the  median  position  of  its  origin  this  last-named 
muscle  is  thus  subjected  to  a  very  considerable  tension.  More- 
over, that  part  of  the  externus  in  contact  with  the  eyeball  is 
greater  than  is  the  case  with  the  other  muscles,  and  it  must  neces- 


168       MUSCULAR   ASTHENOPIA   AND    DYNAMIC   STRABISMUS. 

sarily  participate  in  the  expansion  of  the  eye.  All  these  cir- 
cumstances result  in  an  increased  elastic  tension  of  the  external 
muscles  and  a  consequent  increased  resistance  to  the  action  of 
their  antagonists. 

Finally,  the  deviation  of  the  line  of  vision  from  the  centre  of 
the  cornea  must  be  considered.  Since  this  deviation  is  less  in 
myopia  than  in  erametropia,  the  lines  of  vision  will  intersect  at 
a  greater  distance  in  myopia  than  in  emmetropia,  supposing  the 
position  of  the  cornea  to  be  the  same  in  both  cases.  In  order  to 
attain  the  same  convergence  there  must  be,  on  the  part  of  the  in- 
terni  muscles,  a  stronger  action  in  myopia  than  in  emmetropia. 
This  fact  explains  both  the  relative  divergence  of  the  visual  lines 
during  near  vision  and  the  very  considerable  absolute  divergence 
which  may  be  caused  by  prisms  with  their  refracting  angles  turned 
outward. 

It  is  remarkable  that  in  many  cases,  in  spite  of  a  considerable 
inclination  to  absolute  divergence,  quite  a  respectable  movement 
of  convergence  is  still  possible.  It  is  only  exceptionally  that 
absolute  strabismus  divergens  develops  from  the  relative  diver- 
gence of  myopia.  The  reason  for  this  is,  that  the  limitation  in 
the  movements  of  the  eyes  prevents  any  very  great  divergence, 
and  in  spite  of  relative  divergence  for  near  vision,  still,  for 
distant  vision  the  binocular  visual  act  is  maintained. 

Strabismus  divergens  generally  develops  later  than  convergent 
squint,  as  a  rule,  after  childhood  has  passed. 

The  therapeutic  indications  in  cases  of  relative  divergence 
depending  upon  myopia  have  been  already  mentioned,  on  page 
51.     Absolute  divergence  demands  relief  by  operation. 

MUSCULAR   ASTHENOPIA   AND  DYNAMIC  STRABISMUS. 

We  have  already  learned  that  an  elastic  preponderance  of  the 
external,  or,  what  amounts  to  the  same  thing,  an  insufficiency  of 
the  internal  muscles,  is  the  principal  cause  of  absolute  strabismus 
divergens,  and,  in  connection  with  myopia,  the  cause  of  relative 
divergence  also.  Nevertheless,  insufficiency  of  the  interni  does 
not  always  lead  to  divergence;  although  the  equilibrium  of  the 
muscles  is  destroyed,  binocular  vision  may  be  maintained. 

The  occurrence  of  this  condition  after  recovery  from  paralysis 
of  the  ocular  muscles  has  been  already  mentioned,  page  137.    For 


MUSCULAR   ASTHENOPIA   AND    DYNAMIC   STRABISMUS.       169 

instance,  if  in  a  nearly  recovered  case  of  paralysis  of  the  abdu- 
cens,  in  a  part  of  the  field  in  which  binocular  single  vision  has 
been  restored,  it  be  disturbed  by  prisms  refracting  vertically,  the 
double  images  often  show  a  lateral  deviation  not  dependent  on 
the  action  of  the  prisms,  since  with  the  interruption  of  binocular 
single  vision  there  remains  no  incentive  to  oppose  the  elastic  tend- 
ency of  the  muscles  by  an  unusually  strong  innervation.  In 
a  similar  manner  one  can  detect  in  many  cases,  by  the  help  of 
vertically  refracting  prisms,  during  fixation  on  far  or  near  ob- 
jects, an  inclination  to  convergence  or  divergence,  which,  under 
ordinary  circumstances,  is  overcome  in  the  interest  of  binocular 
single  vision.  Von  Graefe  designated  this  condition  as  dynamic 
squint. 

Insufficiency  of  the  recti  iuterni  can  accordingly  cause  absolute, 
relative,  or  dynamic  strabismus.  In  the  last  case  the  strain  upon 
the  recti  interni,  which  must  be  made  to  maintain  the  convergence 
necessary  while  working,  causes  fatigue  in  those  muscles,  with  the 
same  painful  symptoms  as  occur  in  accommodative  asthenopia, 
depending  there  upon  fatigue  of  the  ciliary  muscle. 

In  making  the  diagnosis  of  this  muscular  asthenopia,  we  must 
determine  first  the  maximum  attainable  convergence,  while  the 
eyes  are  looking  slightly  downward.  If  a  convergence  to  a  dis- 
tance of  from  6  to  8  cm.  cannot  be  reached,  but  if  one  eye  before 
reaching  such  a  point  deviates  outward,  then  there  is  insufficiency 
of  the  recti  interni. 

In  order  to  relieve  the  ocular  muscles  from  the  controlling  in- 
fluence of  binocular  single  vision  one  eye  may  be  covered  during 
convergence  at  the  distance  usual  for  work.  This  is  best  done 
with  a  ground  glass,  which,  when  held  close  to  the  eye,  still  allows 
observation  of  its  position.  When  this  is  done  the  covered  eye 
deviates  outward,  and  returns  again  to  fixation  whenever  the  glass 
is  removed. 

Binocular  single  vision  may  also  be  interrupted  by  holding  in 
front  of  one  eye,  a  prism  with  its  refracting  angle  turned  upward 
or  downward.  If  the  tension  upon  the  inner  muscles  be  excess- 
ive, the  visual  axes  will  diverge  somewhat  upon  interruption  of 
binocular  single  vision.  The  double  images  will  not  stand  di- 
rectly  one  above  the  other,  but  will  be  crossed,  and  at  different 

levels. 

12 


170      MUSCULAR   ASTHENOPIA    AND    DYNAMIC    STRABISMUS. 

According  to  Von  Graefe,*  the  experiment  is  made  as  follows. 
A  large  dot  is  made  on  a  sheet  of  white  paper  and  a  fine  vertical 
line  drawn  through  it.  This  is  laid  before  the  patient  in  the  po- 
sition and  at  the  distance  usual  in  reading.  If  then,  upon  placing 
a  vertically  refracting  prism  before  one  eye,  the  double  images  do 
not  stand  one  above  the  other,  but  are  crossed,  divergence  of  the 
visual  axes  is  indicated.  The  measure  of  this  divergence,  or  of 
the  insufficiency  of  the  interni,  is  given  by  that  prism  which, 
placed  before  the  other  eye  with  its  angle  turned  outward,  causes 
the  two  images  to  appear  exactly  one  above  the  other.  According 
to  Von  Graefe,  the  same  distance  and  fixation-object  should  be 
used  to  determine  what  prisms  may  be  overcome  by  convergence 
and  divergence. 

This  method  of  examination  should  not  be  relied  on  in  deter- 
mining the  condition  of  the  muscles,  without  investigating  at  the 
same  time  the  condition  of  refraction.  For  instance,  if  a  hyper- 
metrope  sees  through  a  vertically  refracting  prism  the  double 
images  of  a  distant  object  not  exactly  one  above  the  other,  but 
separated  laterally  and  homonymous,  this  may  be  due  to  insuf- 
ficiency of  the  recti  externi ;  it  may,  however,  occur  without  that, 
simply  in  consequence  of  a  certain  degree  of  convergence  attending 
the  accommodation  necessary  even  for  distance,  just  as  happens 
under  the  same  circumstances  to  emmetropes  when  they  put  on 
concave  glasses. 

If  in  myopia  of  a  medium  grade  (say  ^  to  yw)  ^'^^  fixation-object 
be  placed  near  the  for  point  and  double  images  be  provoked  by  a 
prism  refracting  vertically,  there  no  longer  exists  any  incentive 
for  maintaining  the  proper  convergence.  If  the  double  images 
cannot  possibly  be  united,  it  is  all  the  same  to  the  myopes  whether 
they  stand  exactly  one  above  the  other  or  at  the  same  time  show 
a  lateral  deviation.  The  retinal  images  remain  distinct,  except 
as  their  clearness  is  diminished  by  the  prisms,  even  with  a  parallel 
direction  of  the  visual  axes. 

Of  course,  when  vision  is  directed  upon  an  object  in  the  neigh- 
borhood of  the  far  point,  the  greatest  possible  degree  of  divergence 
may  be  given  to  the  visual  lines  by  means  of  prisms  with  their 
refracting  angles  turned  outward.     To  determine  the  maximum 

*  Arch.  f.  Ophth.,  B.  viii.  2,  pag.  314. 


MUSCULAR   ASTHENOPIA    AND    DYNAMIC   STRABISMUS.       171 

degree  of  convergence  by  means  of  prisms  with  their  refracting 
angles  turned  inward  is  useless  trouble,  since  it  may  be  done  in  a 
more  direct  and  simpler  way  by  merely  bringing  the  object  fixed 
nearer  to  the  eye. 

Under  all  circumstances,  but  jiarticularly  in  myopia,  conver- 
gence is  maintained  by  a  muscular  effort,  which  is  gladly  relin- 
quished as  soon  as  it  is  no  longer  necessary  in  the  service  of 
binocular  vision.  This  is  especially  apt  to  happen  when  other 
causes  for  fatigue  co-exist,  for  instance,  conjunctival  irritation  or 
those  symptoms  of  irritation  so  common  in  myopia.  Upon  ex- 
amining these  cases  with  prisms  refracting  vertically,  an  inclination 
to  parallelism  of  the  visual  axes  is  almost  always  found,  but  from 
this  it  does  not  follow  that  muscular  asthenopia  is  the  cause  of  all 
symptoms  of  irritation.  These  symptoms  occur,  as  a  rule,  in  my- 
opia of  a  middle  grade,  even  when  there  is  no  asthenopia.  Gen- 
erally, and  especially  when  any  symptoms  of  irritation  exist,  as, 
for  instance,  in  conjunctival  hyperseniia,  myopes  prefer  a  parallel 
position  of  the  visual  axes,  and  make  the  movement  of  conver- 
gence only  when  it  is  necessary  for  binocular  vision. 

The  examination  with  prisms  gives  altogether  different  results 
when  it  is  conducted  with  the  help  of  correcting  concave  lenses. 
The  effort  of  accommodation  then  affects  the  convergence  exactly 
as  in  emmetropia.  In  this  case,  too,  when  binocular  fixation  is 
interrupted,  the  inclination  to  diminish  convergence  is  perceptible. 
At  the  same  time,  however,  the  accommodation  relaxes,  and  as 
soon  as  the  indistinctness  of  the  retinal  images,  caused  by  this,  be- 
comes annoying  to  the  patient,  there  follows  with  the  renewal  of 
the  accommodative  effort  an  increased  innervation  of  the  interni, 
which  in  its  turn  is  often  excessive,  and  causes  a  slight  temporary 
convergence. 

If,  on  the  contrary,  there  follow  under  these  circumstances  a 
considerable  and  permanent  diminution  of  convergence  as  soon  as 
binocular  fixation  is  interrupted  by  prisms,  it  proves  that  there  is 
some  disturbance  in  the  normal  relations  between  the  convergence 
of  the  visual  lines  and  the  tension  of  accommodation. 

In  most  of  these  cases  the  preponderance  of  the  recti  externi 
can  be  demonstrated  when  the  patient  is  directed  to  fix  a  distant 
object.  If,  for  instance,  one  choose  as  the  fixation-object  the  flame 
of  a  candle,  twenty  feet  distant,  double  crossed  images  often  appear 


172      MUSCULAR   ASTHENOPIA   AND   DYNAMIC  STRABISMUS. 

as  soon  as  the  two  fields  of  vision  are  diflPerentiated  by  placing  a 
red  glass  in  front  of  one  eye.  This  is  much  more  certain  to 
happen  when  binocular  fixation  is  made  impossible  by  a  weak 
prism  refracting  vertically. 

Moreover,  a  much  greater  divergence  of  the  visual  axes  may 
be  caused  in  cases  of  myopia  by  prisms  with  their  refracting 
angles  turned  outward  than  is  possible  under  normal  relations; 
or,  in  other  words,  much  stronger  prisms,  even  up  to  20°  or  more, 
can  be  overcome  by  divergence. 

It  is  remarkable  that  in  marked  cases  of  elastic  preponderance 
of  the  externi  the  nearest  point  to  be  attained  by  convergence  is  by 
no  means  always  at  a  greater  distance  than  normal  from  the  eyes. 

Muscular  asthenopia  is  not  near  so  frequent  as  accommodative 
asthenopia.  It  may  occur  in  every  condition  of  refraction, — in 
emmetropia,  hypermetropia,  or  astigmatism.  Cases  of  but  slight 
myopia  are  those  generally  associated  with  muscular  asthenopia. 
In  the  higher  grades  of  myopia  the  fatigue  of  the  recti  interni  is 
avoided  by  the  occurrence  of  relative  divergence.  The  patient, 
for  instance  in  reading,  begins  binocularly ;  soon,  however,  one 
eye  deviates  outward  involuntarily  and  unnoticed.  The  patients 
do  not  in  such  cases  complain  of  fatigue,  but  simply  notice  that 
one  page  seems  to  project  over  the  other.  They  generally  learn 
to  escape  the  annoyances  of  diplopia. 

In  the  treatment  of  muscular  asthenopia  we  may  palliate  the 
condition  by  the  help  of  prismatic  glasses,  or  it  may  be  cured  by 
operation. 

It  follows  from  what  has  been  said  on  page  93,  concerning  the 
use  of  prismatic  spectacles,  that  they  may  be  used  with  special 
advantage  when  it  is  possible  to  employ  a  working  distance  of  at 
least  10  or  12  inches. 

It  is  generally  advisable  to  begin  the  treatment  by  these  pallia- 
tive means,  since  the  abnormal  relations  in  the  tension  of  the  mus- 
cles may  disappear  in  time.  I  have  observed  this  especially  in 
those  cases  in  which,  in  spite  of  a  decided  inclination  to  divergence, 
the  normal  near  point  for  convergence  could  still  be  reached 
without  much  difficulty. 

Prisms  of  perhaps  3  and  at  most  6  degrees  are  set  in  spectacle 
frames  with  their  refracting  angles  turned  outward.  They  are  of 
course  to  be  used  only  for  near,  and  never  for  distant  objects,  since 


UPWARD    AND    DOWNWARD   SQUINT.  173 

there  is  no  occasion  for  inducing  absolute  divergence  of  the  visual 
lines. 

The  operative  treatment  consists  in  the  tenotomy  of  the  recti 
externi.  Under  certain  circumstances  a  radical  cure  may  be  thus 
accomplished.  The  greatest  care  must,  however,  be  taken  that  by 
this  operation  a  simple  dynamic  divergence  be  not  converted  into 
a  real  converging  squint.  The  tenotomy  may  be  resorted  to  with- 
out fear  of  this  result,  in  cases  where  the  existence  of  an  elastic 
preponderance  of  the  externi  is  demonstrated.  If  during  distant 
vision  an  inclination  to  divergence  be  apparent,  and  if  at  the  same 
time  unusually  strong  prisms  can  be  overcome  by  divergence  of 
the  visual  lines,  it  is  certain  that  after  tenotomy  of  the  externi 
there  will  be  no  annoying  convergence. 

As  a  rule,  the  tenotomy  is  to  be  performed  on  that  eye  which, 
during  the  maintenance  of  convergence,  shows  the  greater  inclina- 
tion to  deviate  outward.  In  many  cases  the  tenotomy  of  both 
externi  seems  to  be  necessary. 

If  insufficiency  of  the  interni  occur  without  elastic  preponder- 
ance of  the  externi,  the  tenotomy  is  to  be  avoided,  and  only  the 
use  of  prismatic  glasses  can  be  resorted  to. 

UPWARD    AND    DOWNWARD   SQUINT. 

Associated  with  a  high  degree  of  convergence  there  often  occurs, 
as  already  mentioned,  a  vertical  deviation,  generally  simply  as  an 
accompanying  symptom  which  demands  no  special  correction,  and 
disappears  when  the  convergence  is  relieved. 

Another  much  rarer  group  of  cases  are  those  in  which  the  ver- 
tical deviation  exists  without  any  marked,  or  with  only  very  slight, 
lateral  squint,  and  shows  a  decidedly  concomitant  character.  For 
instance,  if  the  eye  which  squints  upM'ard  be  used  for  fixation,  the 
other  makes  an  accompanying  movement  downward. 

The  vertical  deviation  under  these  circumstances  does  not  remain 
the  same  in  all  directions  of  vision.  As  a  rule,  the  upward  devi- 
ation is  greatest  when  vision  is  directed  toward  the  median  plane, 
and  least  when  directed  outward ;  while,  on  the  contrary,  in  down- 
ward squint,  the  deviation  is  greatest  when  looking  outward,  and 
disappears  in  looking  inward.  While  the  cornea  of  the  unaffected 
eye  moves  through  a  horizontal  course,  that  of  the  squinting  eye  is 
in  a  plane  whose  direction  is  downward  and  outward. 


174  OPERATION    FOR   STRABISMUS. 

It  is  not  possible  to  refer  this  peculiar  movement  to  the  action 
of  any  particular  muscle.  It  is  very  seldom  that  the  vertical 
deviation  is  the  same  in  all  directions  of  vision,  and  when  such  is 
the  case  it  must  be  regarded  as  due  to  an  increased  tension  of  the 
two  muscles  acting  upward  or  downward  as  the  case  may  be. 

Double  images  exist  in  most  cases  of  vertical  deviation. 

In  respect  to  operative  treatment,  the  same  principles  are  ap- 
plicable as  were  laid  down  with  reference  to  vertical  deviation 
remaining  after  paralysis  of  the  ocular  muscles. 

OPERATION    FOR   STRABISMUS. 

The  operative  treatment  of  strabismus  was  first  introduced  by 
vStromeyer,  in  1838,  and  in  1839  was  practised  methodically  by 
Dieffenbach. 

The  first  object  of  the  operation  for  squint,  as  now  performed, 
is  to  divide  the  tendon  of  the  shortened  muscle  close  to  its  inser- 
tion u})on  the  sclera.  The  direct  attachment  of  the  muscle  to 
the  eyeball  is  thus  destroyed,  but  indirect  attachments  remain,  by 
means  of  the  connections  of  the  muscle  with  the  capsule  of  Tenon 
and  with  the  conjunctiva.  The  effect  of  the  operation  is  greater 
or  less,  according  as  these  indirect  attachments  are  more  or  loss 
divided. 

The  following  method  of  operation  is  generally  the  best.  The 
patient  is  laid  in  a  suitable  position  and  aneesthetized.  The  lids 
are  held  apart  by  an  assistant  or  by  a  speculum.  With  the  fixation 
forceps  the  eyeball  is  seized  at  a  point  near  the  cornea  and  dia- 
metrically opposite  the  muscle  to  be  divided.  The  eyeball  is 
rolled  over  into  a  position  which  leaves  the  field  of  operation  free. 
Exactly  above  the  tendon  of  the  muscle,  or  a  little  in  front  of  it, 
the  conjunctiva  is  seized  with  a  pair  of  forceps,  lifted  into  a  fold, 
and  an  incision  made.  This  incision  may  be  made  either  parallel 
with  the  direction  of  the  muscle, — the  advantage  in  that  method 
being  that  the  wound  gapes  less  after  the  operation, — or  may  be  par- 
allel to  the  line  of  insertion  of  the  muscle,  in  which  case  the  latter 
is  somewhat  better  exposed.  The  conjunctiva  is  now  loosened 
toward  the  periphery  with  the  scissors,  in  case  of  strabismus  con- 
vergens,  as  far  as  the  caruncle.  Then  the  muscle  is  grasped  by  the 
forceps  close  behind  its  insertion ;  when  possible  the  whole  breadth 
of  the  muscle  should  be  seized.     The  insertion  of  the  muscle  is 


OPERATION    FOR   STRABISMUS.  175 

first  pierced  in  the  middle  with  the  scissors,  one  blade  being  thrust 
between  the  muscle  and  the  sclera,  first  to  the  one  side  and  then 
to  the  other,  and  the  tendon  is  divided  close  to  the  sclera.  By- 
passing in  a  strabismus-hook  the  operator  satisfies  himself  that  no 
tendinous  threads  remain  in  the  neighborhood  of  the  insertion. 
It  is  important  to  know  the  position  of  the  insertions  of  the  vari- 
ous ocular  muscles.  That  of  the  rectus  internus,  measured  in  the 
horizontal  meridian,  is  6  mm.  from  the  margin  of  the  cornea,  that 
of  the  externus  about  8  mm.,  and  those  of  the  superior  and  in- 
ferior from  7  to  8  mm. 

I  cannot  agree  with  Von  Graefe  in  his  oft-repeated  advice  to 
make  the  conjunctival  wound  as  near  as  possible  to  the  margin  of 
the  cornea.  If  one  does  so,  he  finds  himself  so  far  from  the  in- 
sertion of  the  tendon  that  the  blunt  hook  which  he  must  insert 
under  it  before  he  can  cut  it  must  be  thrust  a  relatively  long  dis- 
tance under  the  conjunctiva.  In  doing  this  the  conjunctival  wound 
is  generally  torn  larger,  and  still  more  when,  according  to  direc- 
tions, the  handle  of  the  hook  is  turned  so  as  to  draw  the  tendon 
tense. 

The  scissors  used  in  the  operation  should  be  blunt-pointed  and 
slightly  curved  on  the  flat. 

After  the  operation,  the  absolute  separation  of  the  tendon  from 
the  sclera  is  shown  by  a  marked  limitation  of  the  movement  of 
the  eyeball  toward  that  side.  There  should  be  only  a  limitation, 
and  not  abolition  of  movement,  because  the  muscle  still  remains 
in  indirect  connection  with  the  sclera.  If,  on  the  contrary,  there 
be  no  limitation  of  movement,  or  if  it  be  too  slight,  there  is 
reason  to  suspect  that  some  tendinous  threads  about  the  margin 
of  the  insertion  remain  uncut.  These  are  to  be  found  with  the 
strabismus-hook  and  divided.  It  is  very  seldom  that  the  muscle 
is  attached  by  strong  connective  tissue  to  the  sclera  behind  its  in- 
sertion. In  these  cases  a  careful  detachment  of  the  muscle  back 
to  the  posterior  end  of  this  insertion  is  indicated,  but  it  is  not 
always  practicable.* 

Except  in  these  few  cases,  the  operation  should  not  be  re- 
garded as  completed  until  marked  limitation  of  movement  is 
perceptible. 

*  Von  Graefe,  Arch.  f.  Ophthal.,-  B.  ix.  2,  pag.  32. 


176  OPERATION    FOR   STRABISMUS. 

If,  after  the  operation,  the  conjunctival  wound  gapes  too  widely, 
it  may  be  closed  with  a  fine  silken  suture.  If  it  be  intended  only 
to  unite  the  conjunctival  wound  with  the  suture,  it  is  well  to  place 
it  parallel  to  the  insertion  of  the  muscle,  and  pass  it  simply 
through  the  conjunctiva  so  as  to  include  as  little  of  the  sub- 
conjunctival tissue  as  possible,  because  when  so  done  it  will  cut 
through  of  itself  in  a  few  days  and  not  require  to  be  removed. 

The  after-treatment  consists  in  cold  dressings  or  the  immediate 
application  of  a  light  bandage. 

The  mechanical  effect  of  the  operation  for  squint  may  be  ex- 
plained in  the  following  manner.  After  the  detachment  of  the 
tendon  from  its  insertion,  the  muscle  retracts  as  far  as  its  elastic 
tension  demands  and  its  connections  with  the  capsule  of  Tenon  and 
the  conjunctiva  allow.  Simultaneously  the  antagonistic  muscle 
draws  the  eye  around  until  the  equilibrium  is  reached. 

After  some  days  union  takes  place  between  the  muscle  and  the 
sclera  in  a  line  parallel  with  the  original  insertion,  but  farther 
back.  The  influence  of  the  muscle  upon  the  eyeball  then  becomes 
direct  and  stronger,  the  movement  increases,  but  generally  at  the 
same  time  diminishes  somewhat  the  effect  upon  the  position  of 
the  cornea  which  Avas  perceptible  immediately  after  the  operation. 
Probably  the  anterior  end  of  the  detached  muscle  is  drawn  some- 
what forward  by  the  contraction  of  cicatricial  tissue  which  develops 
in  the  wound.  This  effect  is  greater  the  weaker  the  antagonistic 
muscle.  It  may  happen  in  this  way  that  an  effect  which  imme- 
diately after  the  operation  was  satisfactory,  becomes  insufficient. 

It  is  evident  from  what  has  been  said  that  the  ultimate  results 
in  respect  to  the  position  of  the  cornea,  obtained  by  the  operation 
for  squint,  vary  greatly  in  different  cases.  If  tenotomy  of  the 
rectus  extern  us  be  performed  on  account  of  muscular  asthenopia, 
it  is  an  error  and  an  over-effect  of  the  operation  to  cause  a  perma- 
nent change  in  the  position  of  the  eyes.  In  these  cases  we  have 
to  thank  the  pre-existing  elastic  relations  of  the  ocular  muscles, 
and  the  regulating  influence  of  binocular  fixation,  that  the  con- 
vergence generally  existing  immediately  after  operation  does  not 
remain  permanent.  But  it  may  happen  without  the  influence  of 
binocular  vision  that  the  ultimate  effect  of  the  operation  is  very 
slight.  The  operation  for  squint  has  been  mistakenly  regarded 
as  if  it  consisted  essentially  in  setting  back  the  insertion  of  the 


OPERATION   FOR  STRABISMUS.  177 

shortened  muscle ;  but  it  is  perfectly  clear  that  this  alone  would 
exert  no  influence  upon  the  position  of  the  eye  if  there  were  not 
an  antagonistic  force  drawing  it  over  to  the  other  side.  In  the 
operation  of  tenotomy  we  count  upon  a  sufficient  elastic  strength 
in  the  antagonist,  and  this  is  the  element  which  cannot  always  be 
relied  upon  with  certainty,  since  it  is  probable  that  elastic  tension 
and  muscular  contractibility  are  two  diiferent  properties,  and  the 
result  of  an  operation  is  essentially  influenced  by  the  elastic  ten- 
sion of  the  antagonist. 

In  many  cases  of  hypermetropia  with  strabismus  convergens, 
the  correction  of  the  hypermetropia  is  absolutely  necessary  after  an 
operation,  even  when  there  is  no  binocular  fixation.  An  annoying 
strabismus  convergens  returns  whenever  the  use  of  convex  glasses 
is  discontinued.  This  may  be  well  understood  from  the  relation 
which  has  been  shown  to  exist  between  hypermetropia  and  stra- 
bismus convergens ;  it  is  only  remarkable  that  it  does  not  occur 
often  er. 

Finally,  the  effect  of  tenotomy  is  somewhat  different  on  the  dif- 
ferent muscles ;  it  is  less  for  divergent  than  for  convergent  squint. 
In  those  disfiguring  cases  of  strabismus  divergens  in  which  the 
movement  of  convergence  is  so  far  lost  that  parallelism  of  the 
visual  lines  cannot  be  attained,  the  effect  of  simple  tenotomy  of 
the  externus  of  the  squinting  eye  is  likely  to  be  very  slight.  The 
explanation  of  this  fact  is  not  so  simple.  The  rectus  internus  is 
in  these  cases  lengthened  and  weakened,  it  is  true,  by  continuous 
stretching,  but  still  scarcely  more  than  the  rectus  externus  in  ex- 
treme cases  of  strabismus  convergens.  It  is  true  that  a  longer 
portion  of  the  rectus  externus  lies  in  contact  with  the  eyeball  than 
is  the  case  with  the  rectus  internus,  but  that  does  not  prevent  very 
considerable  strabismus  convergens  in  cases  where  simple  tenotomy 
of  the  externus  has  been  performed  when  the  proper  indications 
for  the  operation  did  not  exist.  Although  experience  shows  that 
simple  tenotomy  of  the  externus  of  the  squinting  eye  in  cases  of 
high  degree  of  divergence  is  almost  without  result,  the  explanation 
of  this  fact  ought  not  to  be  sought  for  wholly  in  the  rectus  ex- 
ternus and  its  antagonist.  It  is  probable  that  the  obliqui  muscles 
play  a  part  in  this  matter  which  has  not  yet  been  recognized. 
Aside  from  their  muscular  contractibility  and  regarding  only  the 
elastic  tension  of  the  obliqui,  this  will  be  greatest  when  the  mus- 


178  OPERATION    FOR   STRABISMUS. 

cles  embrace  the  eye  in  the  direction  of  a  great  circle,  as  is  the 
case  when  vision  is  directed  strongly  inward.  The  elastic  tension 
of  the  obliqui  muscles  has  in  that  ])osition  only  the  effect  to  draw 
the  eye  forward  in  the  plane  of  the  muscles.  On  the  contrary, 
when  vision  is  directed  more  outward,  the  obliqui  no  longer  em- 
brace the  posterior  part  of  the  eye  in  the  direction  of  a  great  cir- 
cle; accordingly  they  are  less  stretched,  and,  moreover,  only  a 
part  of  their  elastic  tension  is  expended  in  drawing  the  eye  for- 
ward ;  the  other  part  will  be  exerted  in  turning  the  posterior  pole 
of  the  eye  inward  and  the  cornea  outward. 

The  consequences  of  this  are  the  following.  In  high  degrees 
of  strabismus  divergens  the  squinting  eye  is  seldom  or  never 
turned  so  far  inward  that  the  obliqui  assume  the  direction  of  a 
great  circle,  or  experience  so  great  a  strain  as  they  do  under  phys- 
iological relations ;  since,  though  the  power  of  turning  the  eye 
inward  may  still  remain,  it  is  in  fact  but  little  exercised.  The 
obliqui  of  the  diverging  eye  are  thus  less  stretched  than  under 
normal  relations,  and  it  is  possible  that  their  extensibility  for  this 
reason  becomes  so  diminished  that  they  finally  oppose  a  greater 
elastic  resistance  to  motion  in  the  median  direction  than  they  do 
under  physiological  conditions.  Now,  since  the  tension  of  the 
obliqui  is  not  affected  by  the  operation,  it  is  plain  that  when  in 
old  cases  of  extreme  strabismus  divergens  they  have  lost  their 
extensibility  they  will  act  after,  just  as  before  the  operation,  to 
turn  the  cornea  outward  and  to  lessen  the  effect.  In  strabismus 
convergens,  moreover,  the  superior  and  inferior  recti  muscles  jjlay 
a  similar  though  less  effectual  part. 

Where  there  is  sufficient  elastic  tension  of  the  antagonistic  mus- 
cle, a  correction  of  3  or  4  mm.  in  the  position  of  the  eye  may  be 
accomplished  by  the  tenotomy  of  the  rectus  internus,  and  still  the 
movements  of  the  eye  be  not  unduly  interfered  with  by  too  ex- 
tensive loosening  of  the  indirect  connections  between  the  muscle 
and  the  eyeball. 

The  farther  the  insertion  of  the  muscle  is  set  back  upon  the 
sclera,  the  sooner  will  the  muscle  in  its  conti'action  attain  the 
limit  beyond  which  it  can  exercise  no  further  influence  upon  the 
position  of  the  eye.  There  will  remain  a  limitation  of  movement 
in  the  same  direction  in  which  the  eye  formerly  squinted.  This 
limitation  of  movement  is  more  noticeable  in  conversrino-  than  in 


OPERATION    FOR   STRABISMUS.  179 

associated  movements.  For  a  somewhat  similar  phenomenon  and 
one  depending  on  the  same  reasons,  see  page  128. 

A  correction  of  from  3  to  4  mm.,  which  may  be  accomplished 
without  any  annoying  limitation  of  movement,  is  certainly  for  most 
cases  of  squint  not  sufficient,  but  there  is  a  very  simple  method 
by  which  we  may  double  the  effect  of  the  correction  without  too 
great  a  sacrifice  of  movement ;  this  is  by  dividing  the  operation 
symmetrically  between  the  two  eyes.  If,  for  instance,  in  stra- 
bismus convergens  we  divide  the  two  interni,  or  in  strabismus 
divergens  the  two  externi,  the  result  as  affecting  the  correction 
of  position  will  be  cumulative,  while  the  defect  in  movement 
toward  either  side  of  the  visual  field  is  very  slight. 

If  it  can  be  foreseen  with  certainty  that  at  least  two  operations 
are  necessary,  both  eyes  may  be  operated  on  at  the  same  sitting 
in  order  to  economize  time.  If  the  greatest  possible  effect  is 
aimed  at,  it  is  well  to  fix  the  visual  axes  for  24  or  36  hours  in  a 
position  slightly  beyond  the  one  desired.  The  method  is  as  fol- 
lows. Near  the  outer  margin  of  the  cornea  a  threaded  needle  is 
])assed  through  the  conjunctiva  just  above  the  horizontal  meridian, 
and  is  brought  out  about  2|  mm.  lower  down;  it  is  then  again 
inserted  about  2^  mm.  above  the  first  point  and  brought  out  just 
below  the  horizontal  meridian.  The  conjunctiva  through  an  ex- 
tent of  about  5  mm.  is  thus  embraced  very  securely.  The  ends 
of  the  thread  are  then  drawn  upon,  but  not  tied  in  a  knot,  and  in 
case  of  strabismus  convergens  are  carried  over  upon  the  temple, 
there  to  be  fastened  with  adhesive  plaster  and  collodium.  In 
strabismus  divergens  the  threads  are  fastened  on  the  bridge  of  the 
nose,  and  in  cases  where  the  nose  is  so  low  as  to  allow  the  threads 
to  rub  upon  the  cornea,  they  must  be  raised  by  a  roll  of  adhesive 
plaster.  To  remove  the  thread,  cut  one  end  close  to  the  conjunc- 
tiva, and  the  stitch  can  then  be  easily  withdrawn.  So  long  as 
the  thread  is  in  position  it  is  well  to  hold  both  eyes  closed  by  a 
bandage. 

If  the  bilateral  operation  does  not  prove  to  be  sufficient,  a  repeti- 
tion on  the  originally  squinting  eye  or  on  both  may  be  undertaken. 

In  order  to  increase  the  effect  of  the  operation,  one  often  hears 
the  advice  given,  to  hold  the  eye,  after  the  operation,  continuously 
in  the  direction  opposite  to  the  squint.  It  is  evident  that  little 
can  be  expected  from  such  an  effort.    Let  any  one  try  how  long  he 


180  OPERATION    FOR   STRABISMUS. 

himself  can  hold  his  eyes  turned  to  one  side;  in  a  few  minutes 
fatigue  is  experienced,  and  involuntarily  the  head  instead  of  the 
eye  is  turned  in  that  direction.  Little  more  can  be  accomplislied 
by  the  so-called  strabismus  spectacles,  which  entirely  cover  one 
eye  and  leave  for  the  other  only  an  eccentric  opening  on  the  side 
opposite  to  the  direction  of  the  squint.  More  is  accomplished 
by  subjecting  the  antagonistic  muscle  to  methodical  orthopedic 
exercise,  either  before  or  some  days  after  the  operation.  Very 
considerable  defects  of  movement  often  disappear  in  a  short  time 
under  this  treatment. 

The  immediate  effect  of  an  operation  for  squint  may  be  dimin- 
ished as  well  as  increased,  though  it  is  not  so  often  necessary  to  do 
so.  The  method  is  by  placing  a  suture  in  the  conjunctival  wound 
parallel  with  the  direction  of  the  muscle,  and  including  some  of 
the  subconjunctival  tissue,  especially  near  the  anterior  end  of  the 
divided  muscle.  The  muscle  is  by  this  means  drawn  forward,  or 
at  least  prevented  from  retracting  too  far. 

A  satisfactory  cosmetic  effect  may  be  almost  always  attained  by 
the  operation  for  squint.  Its  influence  upon  the  sight  in  the 
squinting  eye  and  upon  binocular  vision  has,  on  the  contrary, 
been  over-estimated.  The  oft-repeated  assertion  that  immediately 
after  dividing  one  of  the  ocular  muscles  a  considerable  improve- 
ment in  vision  may  occur,  is  so  contrary  to  all  known  physio- 
logical laws  that  it  can  be  accepted  only  after  further  observations, 
which  must  be  invested  with  every  guarantee  of  accuracy.  Only 
repeated  tests  of  vision,  made  before  the  operation,  and  conducted 
both  with  reference  to  far  and  near  vision,  and  in  respect  to  the 
latter  made  with  the  help  of  convex  glasses  or  Calabar  extract, 
can  be  recognized  as  proving  the  truth  of  so  improbable  a  state- 
ment. In  my  investigations  on  this  subject  I  have  found  no 
immediate  effect  on  the  acuteness  of  vision  from  tenotomy. 

So,  too,  the  operation  for  squint  exercises  no  direct  influence 
upon  the  re-establishment  of  normal  binocular  vision,  except  in 
those  relatively  rare  cases  in  which  there  existed  before  the  oper- 
ation a  normal  correspondence  between  the  two  retinae,  made 
evident  by  the  existing  diplopia. 

Von  Graefe,*  indeed,  asserted  that  only  about  one-half  of  all 

*  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  235. 


OPERATION    FOR   STRABISMUS.  181 

squinting  patients  remained  after  operation  incapable  of  the  binoc- 
ular visual  act,  nevertheless  he  admitted  that  with  reference  to 
tlie  other  half  nothing  more  could  be  asserted  than  the  possibility, 
in  some  way  or  other,  of  bringing  double  iiuages  to  their  notice. 
That,  however,  is  far  from  being  the  re-establishment  of  the 
normal  binocular  visual  act. 

Knapp,*  too,  asserts  that  he  has  attained  the  re-establishment 
of  binocular  fixation  in  fifty  per  cent,  of  his  cases,  but  he  goes  on 
immediately  to  say  that  binocular  fixation  is  not  identical  with 
binocular  single  vision  or  with  stereoscopic  vision,  and  that  in 
many  of  these  patients — capable  of  binocular  fixation — double 
images  could  in  no  way  be  provoked  by  prisms.  Of  course  this 
kind  of  binocular  fixation  has  nothing  in  common  with  normal 
binocular  single  vision. 

In  the  majority  of  cases  it  can  be  proved,  before  operation,  by 
examining  binocular  vision  with  prisms  or  with  the  stereoscope, 
that  no  disposition  exists  to  unite  the  two  retinal  images;  and, 
judging  from  my  experience,  I  hold  it  far  more  probable  that  in 
this  respect  nothing  is  changed  by  the  operation.  Even  in  cases  in 
which  there  was,  before  operation,  good  vision  on  both  sides,  and 
evident  traces  of  a  former  normal  binocular  visual  act,  and  in  which, 
by  the  operation,  apparently  absolutely  correct  fixation  was  attained 
and  retained  for  several  months,  still  no  normal  binocular  vision 
returned.  It  is  true  that,  with  the  help  of  prisms,  double  images 
were  easily  provoked  and  their  positions  rightly  stated;  with  the 
stereoscope,  too,  an  undoubted  union  of  the  two  retinal  images 
could  be  attained,  even  when  this  did  not  always  occur  spontane- 
ously, and,  nevertheless,  Hering's  experiment  gave  negative  re- 
sults. The  operation  had  restored  the  possibility  of  the  normal 
binocular  visual  act,  but  as  a  general  thing  this  possibility  was 
not  taken  advantage  of. 

These  results  are  not  without  practical  consequences.  In  many 
cases  of  strabismus  convergens  with  hypermetropia,  the  lino  of 
vision  deviates  inward  from  the  centre  of  the  cornea  more  than 
usual.  Just  as  with  proper  binocular  fixation  this  condition 
causes  an  apparent  strabismus  divergens,  so  in  the  case  of  strabis- 
mus convergens  it  has  as  a  consequence,  that  a  satisfactory  position 

*  Klin.  Monatsbl.,  1863,  pag.  472. 


182  OPERATION    FOR   STRABISMUS. 

as  regards  cosmetic  effect  may  be  obtained  in  spite  of  a  persistent 
convergence  of  the  visual  lines,  which  is  perfectly  apparent  when 
the  eyes  are  used  alternately  for  fixation.  The  removal  of  this 
slight  convergence,  when  there  is  no  prospect  of  restoring  normal 
binocular  vision,  would  be  no  advantage  to  the  patient,  but  an 
apparent  strabismus  divergens  would  be  caused  where  before  the 
cosmetic  effect  was  satisfactory. 

The  fact  that  in  many  cases  of  hypermetropia  the  lines  of 
vision  deviate  unusually  far  inward  from  the  centre  of  the  cornea, 
may  favor  the  occurrence  of  strabismus  convergens;  at  all  events, 
it  makes  the  operation  easier. 

But  after  operation,  even  if  a  slight  remaining  convergence  of 
the  visual  axes  be  not  hidden  by  a  deviation  outward  of  the  corneal 
axes,  it  is  better,  in  the  operation  for  convergent  squint,  rather  to 
do  too  little  than  too  much.  It  does  no  harm  if  a  slight  degree 
of  convergence  does  remain,  for  a  gradual  improvement  in  posi- 
tion may  be  hoped  for.  On  the  other  hand,  it  is  to  be  feared  that 
a  slight  divergence  remaining  after  operation  will  increase,  and  in 
time  become  a  deformity. 

It  is  not  necessary  in  all  cases  of  strabismus  convergens  with 
hypermetropia,  to  correct  this  with  convex  glasses,  after  operation; 
still,  cases  occur  in  which  the  correction  of  the  hypermetropia 
is  necessary  in  order  to  overcome  the  squint.  The  necessity  of 
this  is  always  to  be  suspected  in  cases  where  the  result  is  at  first 
satisfactory,  but  where  a  few  weeks  after  the  operation  convergence 
reappears. 

Finally,  mention  should  be  made  of  certain  peculiarities  in  the 
movements  of  the  eyes,  which  may  occur  after  the  operation  for 
squint.  After  the  rectus  intern  ns  has  been  set  back  on  one  side 
there  often  appears  a  remarkable  inequality  in  the  squinting  angle 
upon  change  of  fixation.  If,  for  instance,  there  was  strabismus 
convergens  on  the  right  side  of  from  6  to  7  mm.,  which,  by  set- 
ting back  the  right  rectus  internus,  has  been  reduced  to  3  or  4 
mm.,  it  may  happen  that  during  fixation  with  the  right  eye  the 
left  eye  will  deviate  inward,  not  3  or  4  mm.,  but  6  or  7  mm. 
While  the  rectus  externus  of  the  right  eye  turns  that  eye  3  or  4  mm. 
to  the  right,  the  rectus  internus  of  the  left  eye  turns  it  simulta- 
neously 6  or  7  mm.  in  the  same  direction;  there  appears,  accord- 
ingly, to  be  a  striking  inequality  in  the  associated  movements. 


OPERATION    FOR    STRABISMUS.  183 

This  phenomenon  is  more  explicable  when  one  remembers  that  in 
such  cases  not  only  an  associated  but  at  the  same  time  an  accom- 
modative movement  is  involved.  Generally,  the  object  fixed  is 
near  enough  to  require,  even  in  emmetropia,  an  effort  of  accom- 
modation. If  there  be  hypermetropia  of  different  degrees  in  the 
two  eyes,  lio  other  explanation  need  be  sought,  as  under  these  cir- 
cumstances alone,  even  before  the  operation,  there  will  be  evident 
inequality  of  the  squinting  angles  upon  change  of  fixation.  But 
even  when  there  is  no  difference  in  refraction,  the  innervation  of 
the  recti  interni  muscles,  associated  with  the  accommodation,  may 
cause  greater  convergence  in  the  eye  not  operated  on  than  in  the 
other,  the  insertion  of  whose  internus  has  been  set  back,  and 
whose  movement  has  thereby  been  limited.  The  limitation  in 
movement  is  more  apparent  during  accommodation  than  during 
associated  movements. 

It  is  often  observed,  after  operation  for  squint,  that  the  squint- 
ing eye,  when  the  effort  is  made  to  use  it  for  fixation,  shoots  with 
a  twitching  movement  beyond  its  mark  before  it  settles  in  steady 
fixation.  This  phenomenon,  when  it  occurs,  is  generally  observable 
only  for  some  few  days  after  the  operation,  and  then  gradually  dis- 
appears. Evidently  in  these  cases  the  normal  relation  between  the 
eccentric  position  of  the  retinal  image  and  the  ocular  movement 
which  must  be  made  in  order  that  the  image  be  cast  upon  the 
macula  lutea,  is  broken  up  and  a  new  relation  gradually  estab- 
lished. 

Since  many  cases  of  strabismus  convergens  occur  in  the  first 
years  of  childhood,  the  question  often  arises  whether  the  opera- 
tion for  squint  may  properly  be  undertaken  at  that  period  of  life. 
In  general,  the  question  may  be  answered  affirmatively ;  it  is 
indeed  possible  that  the  restoration  of  the  normal  visual  act  is 
more  likely  to  happen  at  such  an  age  than  later.  But,  on  the 
other  hand,  it  is  to  be  remembered  that  the  assistance  to  be  ob- 
tained in  many  cases  of  strabismus  convergens,  by  correcting  the 
hypermetropia,  can  be  taken  advantage  of  only  at  a  more  ad- 
vanced age.  It  is  generally  best  to  wait  until  the  mental  devel- 
opment of  the  child  is  such  that  at  least  an  exact  examination  is 
practicable.  Up  to  this  time  separate  exercise  of  the  squinting 
eye,  both  in  movement  and  in  vision,  should  be  practised.  This 
is  best  accom})lished  by  causing  the  patient  to  wear  during  several 


184  OPERATION    FOR    STRABISMUS. 

hours  of  each  clay  a  pair  of  strabismus  spectacles,  so  made  as  to 
cover,  with  au  opaque  glass,  the  normal  eye,  and  with  an  eccentric 
opening  for  the  other,  on  the  side  opposite  to  the  direction  of  the 
squint. 

It  is  often  beneficial  to  practise  methodically,  looking  to  one 
side.  It  is  frequently  the  case  that  the  outward  movement  of  the 
eye  used  for  fixation,  as  well  as  the  squinting  one,  is  defective, 
and  is  improved  by  practice.  The  strength  thus  given  to  the 
abducens  is  useful  when,  somewhat  later,  an  operation  for  squint 
is  performed. 

Brino-ins;  forward  the  insertion  of  an  ocular  muscle  has  hitherto 
been  practised  principally  with  the  object  of  relieving  deformities 
which  remain  as  the  result  of  excessive  effect  produced  by  the 
operation  for  squint.  It  is  not  proposed  in  this  place  to  enter 
upon  the  history  of  this  operation,  but  simply  to  describe  a 
method  which  I  think  combines  all  the  good  points  of  the 
various  operations  practised  by  J.  Guerin,  Von  Graefe,  Critchett, 
Knapp,  Liebreich,  and  Snellen. 

In  the  first  place  the  shortened  muscle  is  divided,  as  above 
described,  and  the  antagonist  is  then  brought  forward  in  the  fol- 
lowing manner.  An  incision  is  made  in  the  conjunctiva  directly 
above  and  over  the  whole  extent  of  the  insertion  of  the  muscle. 
The  conjunctiva  and  subconjunctival  tissue  are  then  loosened  from 
the  sclera  by  the  scissors,  as  far  as  the  margin  of  the  cornea,  and 
over  a  vertical  extent  corresponding  to  the  width  of  the  insertion 
of  the  muscle  (10  to  12  mm.).  The  attachments  between  the 
anterior  surface  of  the  muscle  and  the  conjunctiva  are  also  divided 
back  to  a  distance  of  about  5  mm. 

Since  in  this  operation  the  conjunctiva,  especial ly*near  the  cor- 
neal margin,  should  not  be  punctured,  it  is  best  to  use  round- 
pointed  scissors. 

At  one  end  of  the  insertion  of  the  muscle  an  incision  is  made 
in  the  capsule  of  Tenon,  through  which  a  fiat,  blunt  hook  is 
thrust  between  the  muscle  and  the  sclera.  The  point  of  the 
hook  is  brought  out  through  another  incision  made  at  the  other 
end  of  the  insertion.  The  sutures  are  now  to  be  inserted  in  the 
muscle. 

A  fine  waxed  silk  thread,  provided  with  a  needle  at  each  end. 


I 


OPERATION    FOR   STRABISMUS.  185 

is  passed  along  the  hook  under  the  muscle,  and  the  needles  passed 
through  it  from  the  scleral  surface  outward,  in  such  a  manner  that 
the  loop  includes  a  portion  of  the  middle  of  the  tendon,  2  or  3 
ram.  in  breadth.  A  thread  is  then  placed  in  a  similar  manner 
near  each  end  of  the  insertion. 

The  insertion  is  then  divided  from  the  sclera,  leaving  the  three 
threads  in  the  end  of  the  severed  tendon.  The  threads  are  then 
brought  from  the  scleral  surface  outward,  through  the  conjunc- 
tival flap,  near  the  margin  of  the  cornea,  and  tied  fast.  To  assist 
in  their  recognition  it  is  well  to  have  the  sutures  of  different 
colors. 

One  end  of  each  suture  is  cut  oiF  closely,  while  the  other  is 
left  sufficiently  long  to  make  its  removal  on  the  second  or  third 
day  eiasy.  To  avoid  altogether  the  difficult  task  of  removing  the 
sutures,  fine  catgut  may  be  used  instead  of  silk,  and  in  that  case 
both  ends  of  the  suture  are  cut  off  close  to  the  knot.  The  con- 
junctival wounds,  when  it  appears  necessary,  may  be  closed  by 
sutures. 

As  after-treatment,  it  appears  best  to  use  ice-dressings  for 
twenty-four  or  thirty-six  hours,  and  then  apply  a  pressure- 
bandage. 

The  method  here  recommended,  of  inserting  the  sutures  in  the" 
muscle  before  it  is  detached  from  the  sclera,  greatly  facilitates 
the  operation.  If,  according  to  the  hitherto  usual  method,  the 
muscle  be  detached  before  securing  it  with  the  sutures,  it  retracts 
by  virtue  of  its  elasticity ;  to  draw  it  forward,  it  must  be  searched 
for  in  the  wound  with  the  forceps,  which  each  time  draw  out 
little  more  than  the  few  bundles  of  fibres  which  they  grasp. 
This  unpleasant  manoeuvre  has  to  be  repeated  for  each  suture 
which  is  inserted. 

The  indications  for  this  procedure  I  consider  more  frequent 
than  has  generally  been  thought.  It  is  advisable  for  all  cases  of 
high  degrees  of  strabismus  with  marked  amblyopia  in  the  squint- 
ing eye. 

If  under  these  circumstances  the  operation  for  squint  be  di- 
vided in  the  usual  manner  between  the  two  eyes,  the  effect  upon 
the  squinting  eye  is  generally  much  less  than  upon  the  other, 
because  its  extern  us  has  become  stretched  and  has  lost  its  elas- 
ticity.    The  greater  part  of  the  correction,  under  these  circum- 

13 


186  .  OPERATION   FOE  STRABISMUS. 

stances,  is  generally  from  the  eifect  of  the  operation  on  the  normal 
eye,  in  which  the  elastic  tension  of  the  antagonistic  muscle  is  normal. 
The  operation  of  bringing  forward  the  insertion  of  this  muscle, 
gives  us  a  very  simple  means  of  increasing  its  elastic  tension,  and 
so  attaining  a  satisfactory  degree  of  correction.  Even  in  extreme 
cases  of  strabismus  convergens,  one  may  almost  always  expect  by 
the  operation  above  described  to  obtain  a  satisfactory  cosmetic 
effect. 

Many  patients  with  very  defective  vision  in  the  squinting  eye 
shrink  from  submitting  their  single  good  eye  to  an  operation  from 
which  only  a  cosmetic  effect  is  to  be  obtained. 

The  objection  raised  by  Von  Graefe,*  that  after  bringing  for- 
ward the  rectus  externus  the  caruncle  remains  too  deeply  sunken 
and  motion  is  too  much  limited,  has  not  been  confirmed  by  my 
experience.  Cases  of  extreme  strabismus  convergens,  with  am- 
blyopia of  the  squinting  eye,  require,  when  simple  tenotomy  is 
performed,  generally  no  less  than  three  operations, — two  on  the 
squinting  and  one  on  the  normal  eye.  In  such  cases  the  caruncle 
of  both  eyes  is  sunken,  and  on  the  squinting  eye  certainly  not 
less  than  after  bringing  forward  the  externus.  As  to  the  limita- 
tion of  movement  following  this  operation,  it  is  not  of  much 
importance,  provided  the  squinting  eye  is  highly  amblyopic. 

If  in  strabismus  convergens  both  eyes  possess  a  fair  degree  of 
vision,  the  tenotomy  of  both  recti  interni  is  to  be  preferred  as  a 
rule,  but  the  operation  for  bringing  forward  the  insertion  of  the 
antagonist  may  still  be  indicated  by  defect  of  motion  toward  that 
side. 

The  operation  of  bringing  forward  the  internus  is  the  treatment 
principally  relied  on  in  disfiguring  strabismus  divergens.  In  cases 
of  extreme  divergence,  with  loss  of  the  power  of  convergence,  the 
effect  of  a  simple  tenotomy  of  the  externus  is  too  slight,  but  the 
effect  also  of  bring-insi;  forward  the  internus  is  somewhat  less  than 
that  of  the  operation  on  the  externus  in  converging  squint.  Since 
the  insertion  of  the  rectus  externus  is  8  mm.  and  that  of  the  rectus 
internus  only  6  mm.  behind  the  margin  of  the  cornea,  the  muscles 
can  be  brought  forward  only  corresponding  distances,  unless  a 
piece  be  cut  from  their  anterior  ends.     Nevertheless,  as  much 

*  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  48. 


NYSTAGMUS.  187 

may  be  expected  from  tenotomy  of  the  extern  us  and  bringing 
forward  the  internus  of  the  squinting  eye  as  from  three  operations 
of  simple  tenotomy  distributed  between  the  two  eyes. 

For  extreme  cases  of  strabismus  divergens  it  is  advisable  to 
divide  the  extern!  and  bring  forward  the  interni  on  both  sides. 

The  red  color  of  the  muscle  which  has  been  brought  forward  is 
perceptible  for  some  time  through  the  conjunctiva.  After  some 
months,  however,  this  slight  cosmetic  defect  disappears. 

NYSTAGMUS. 

By  nystagmus  is  understood  a  continuous  oscillating  movement 
of  the  eyes.  The  movement  is  generally  in  a  horizontal  direction, 
often  with  a  simultaneous  rotation  about  the  visual  axis,  and  very 
seldom  in  a  vertical  direction.  Often  the  nystagmus  is  greater  in 
certain  positions  of  the  eyes  than  in  others,  so  that  such  patients 
see  with  the  eyes  directed  to  one  side  better  than  when  vision  is 
directed  straight  forward. 

Some  cases  are  complicated  by  a  similar  oscillation  of  the  head, 
but  in  an  opposite  direction  about  the  vertical  axis. 

In  most  cases  nystagmus  occurs  in  early  childhood,  perhaps 
even  congenitally,  and  it  appears  that  amblyopia  exercises  the 
greatest  influence  upon  the  develojDment  of  this  anomaly.  Bilat- 
eral amblyopia  congenita,  corneal  opacities  following  blennorrhoea 
neonatorum  or  from  other  causes,  cataracta  congenita,  or  total 
blindness  in  childhood,  often  lead  to  nystagmus.  Cases  of  high 
degrees  of  albinismus  always  present  this  complication.  In  many 
cases  one  eye  is  amblyopic  iii  a  higher  degree  than  the  other. 
Although  the  influence  which  amblyopia,  existing  in  early  child- 
hood, exerts  upon  the  occurrence  of  nystagmus,  is  so  great,  it 
appears  that  there  must  simultaneously  be  other  essential  con- 
current causes,  since  there  are  frequent  cases  of  amblyopia,  either 
congenital  or  acquired  in  early  childhood,  with  absolutely  steady 
fixation.  Normal  acuity  of  vision,  at  all  events,  does  not  appear 
to  exist  in  connection  with  nystagmus,  but  vision  is  often  sufficient 
for  ordinary  occupations,  reading,  etc.,  though  it  is  difficult  to  un- 
derstand how,  during  the  continual  oscillations,  so  distinct  a  recog- 
nition of  the  retinal  images  is  possible.  The  apparent  movements 
of  the  objects  which  would  be  expected  under  the  circumstances 
are  scarcely  ever  noticed  by  the  patients. 


188  NYSTAGMUS. 

In  many  cases,  strabismus  convergens  co-exists,  but  the  operation 
for  its  relief  is  not  contra-indicated  by  the  nystagmus. 

A  very  peculiar  form  of  nystagmus  is  that  which  occurs  prin- 
cipally among  miners.*  The  nystagmus  comes  on  first  while 
working  in  the  darkness  of  the  mines.  As  it  progresses,  it  lasts 
throughout  the  day,  but  greatly  increases  as  twilight  comes  on. 
In  this  condition,  also,  the  nystagmus  is  generally  less  in  certain 
directions  of  vision.  By  bright  daylight,  vision  and  the  ocular 
movements  are  normal,  but  as  the  light  decreases,  not  only  is  the 
nystagmus  increased,  but  a  disproportionate  decrease  in  the  sensi- 
bility of  the  retina  is  apparent  (hemeralopia  from  torpor  retinae). 

It  is  noticeable  that  these  patients  are  greatly  annoyed  and 
made  dizzy  by  the  apparent  movement  of  objects,  due  to  the 
nystagmus.  AVe  recognize  here  again  a  confirmation  of  the  em- 
pirical theory  of  vision.  Individuals  who,  since  their  earliest 
childhood,  have  been  the  subjects  of  nystagmus,  learn  that  the 
movement  of  the  image  which  it  causes  upon  the  retina  does  not 
correspond  to  a  movement  of  the  object ;  if,  on  the  contrary,  the 
normal  visual  act  has  once  become  habitual,  the  movements  of 
the  image  will  be  referred  to  movements  of  the  object. 

This  affection  is  probably  due  to  the  work  done  by  the  insuf- 
ficient light  of  the  miners'  lamps,  and  with  the  eyes  turned  in  a 
very  inconvenient  position.  Frequently  the  miners  work  lying  in 
a  prone  position,  %vith  a  strained  upward  direction  of  the  eyes. 

A  tonic  treatment,  absolute  rest  of  the  eyes,  the  use  of  the  in- 
duction current  and  the  alcoholic  extract  of  nux  vomica  (pill  0.02 
grammes  per  dose  =  ^  grain)  have  been  found  useful. 

Unilateral  nystagmus  has  been  observed.  Zehenderf  has  de- 
scribed a  remarkable  case  of  this  sort ;  one  eye  possessed  normal 
vision,  the  other,  blind  without  any  cause  which  could  be  detected 
by  the  ophthalmoscope,  oscillated  in  a  vertical  direction. 

Nystagmus  often  becomes  less  in  advanced  life ;  treatment  is  of 
no  benefit. 

*  P.  Schroter,  Acquirirter  Nystagmus  bei  Bergleuten,  Klin.  Monatsbl.  fiir 
Augenheilk.,  1871,  pag.  135;  und  Dr.  Nieden,  Ueber  Nystagmus  als  Folge- 
zustand  von  Hemeralopie,  Berliner  klin.  Wochenschrift,  1874,  No.  47. 

t  Klin.  Monatsbl.  f.  Augenheilk.,  1870,  pag.  112. 


PART  SECON^D. 

DISEASES  OF  THE  ORBIT,  LACHRYMAL  APPARATUS, 
LIDS,  CONJUNCTIVA,  CORNEA,  SCLERA,  IRIS,  LENS, 
AND  VITREOUS   BODY. 


189 


AFFECTIONS  OF  THE  ORBIT. 


INFLAMMATION  OF  THE  TISSUES,  AND  CAKIES  OR  NECROSIS 
OF   THE    ORBITAL   WALLS. 

Inflammation  of  the  orbital  adipose  and  connective  tissue 
occurs  rarely  as  an  independent  affection ;  it  is  more  frequent  in 
connection  with  periostitis.  Diseases  of  the  neighboring  bones,  of 
the  base  of  the  skull,  of  the  zygomatic  or  pterygo-palatine  fossa, 
may  cause  an  inflammatory  infiltration  of  the  orbital  tissue,  with 
protrusion  and  loss  of  movement  of  the  eye.  Pathological  pro- 
cesses in  the  neighboring  bony  cavities,  in  the  frontal  and  ethmoidal 
sinuses,  and  in  the  antrum  of  Highmore,  cause  like  effects,  especi- 
ally when  collections  of  pus  or  morbid  growths  in  these  localities 
break  through  the  orbital  w^alls.  The  cause  is  often  a  traumatic 
one,  such  as  a  contusion  or  wound  in  this  region,  the  penetration 
of  a  foreign  body  into  the  orbit,  or  an  operation,  for  instance,  that 
for  squint*  or  for  extirpation  of  the  lachrymal  gland.  Other 
cases  occur  as  puerperal  metastases,  as  one  of  the  symptoms  of 
glanders,  or  in  connection  with  facial  erysipelas.  Typhoid,  scarlet 
fever,  and  smallpox  have  been  suggested  as  causes,  and  Ley  den  f 
has  called  attention  to  the  fact  that  a  hemorrhagic  purulent  in- 
flammation of  the  orbital  tissue  may  result  from  purulent  menin- 
gitis. The  etiological  relation  between  the  two  affections  is  to 
be  explained  by  the  anatomical  connection  which  Schwalbe|  has 
shown  to  exist  between  the  arachnoidal  space  and  the  lymph- 
spaces  which  surround  the  external  sheath  of  the  optic  nerve  and 
pass  over  into  Tenon's  space. 

The  symptoms  vary  according  to  whether  all  the  fatty  tissue  of 
the  orbit  is  diffusely  inflamed  or  the  affection  is  a  more  localized 
one. 

*  Desmarres,  Maladies  des  Yeux,  tome  i.  pag.  170,  Paris,  1854. 
t  Virchow's  Archiv  fiir  path.  Anat.,  1864,  B.  29,  pag.  197. 
J  Archiv  fiir  microscop.  Anatomie,  B.  vi. 

191 


192  INFLAMMATION    OF   THE    ORBITAL   TISSUES. 

Cases  of  the  latter  kind  are  generally  clue  to  traumatic  causes 
or  to  circumscribed  periostitis  of  the  orbit.  Cases  of  diffuse  in- 
flammation of  the  orbital  fat  develop  with  deep-seated  pain  and 
with  inflammatory  swelling,  by  which  the  eyeball  is  forced  for- 
ward in  the  direction  of  the  axis  of  the  orbit ;  at  the  same  time 
all  its  movements  are  quite  uniformly  interfered  with,  since  the 
ocular  muscles  participate  in  the  hemorrhagic  purulent  inflamma- 
tion. Swelling  and  hypersemia  of  the  lids  and  conjunctiva  soon 
follow. 

Chemosis  is  not  always  present,  but  it  may  become  so  consider- 
able that  the  fornix  conjunctiva?  protrudes  and  the  cornea  is  sur- 
rounded by  a  wall-like  swelling.  If  the  protrusion  of  the  eyeball 
be  but  slight,  it  may  be  entirely  masked  by  the  chemosis,  and 
under  these  circumstances,  especially  if  the  development  of  the 
disease  has  not  been  followed  from  the  beginning,  there  is  danger 
of  mistaking  it  for  blennorrhoea,  if  that  error  be  not  guarded 
against  by  observing  the  absence  of  the  characteristic  secretion. 
The  swelling  of  the  lids,  especially  of  the  upper  one,  is  generally 
considerable;  the  skin  is  dark  red,  smooth,  and  shining;  disturb- 
ances of  the  general  condition,  fever,  etc.,  usually  are  present. 

Resolution  does  not  often  occur;  the  inflammation  generally 
goes  on  to  suppuration.  The  skin  becomes  a  darker  red;  upon 
everting  the  lids  the  fornix  conjunctivae  appears  swollen  and  often 
yellow  from  the  pus  beneath.  Fluctuation  may  be  detected  be- 
tween the  eyeball  and  the  orbital  wall.     Finally  the  abscess  breaks. 

Purulent  periostitis  of  the  orbit  may  cause  nearly  the  same 
symptoms  as  genuine  inflammation  of  the  orbital  fatty  tissues,  and 
may  with  the  greatest  probability  be  assumed  to  exist  when  the 
margin  of  the  orbit  is  sensitive  to  pressure.  According  to  Von 
Graefe,*  the  skin  and  the  subcutaneous  connective  tissue  do  not 
so  soon  become  involved  in  periostitis  as  in  inflammation  of  the 
fatty  tissue. 

Moreover,  the  secondary  participation  of  the  connective  tissue 
is  apt  in  periostitis  to  concentrate  in  the  neighborhood  of  the 
affected  spot,  and  the  eyeball  is  therefore  more  frequently  forced 
to  one  side;  the  limitation  of  movement,  too,  is  greater  in  some 
directions  than  in  others.     Nevertheless,  the  diagnosis  is  often 

*  Klin.  Monatsbl.  fiir  Augenheilk.,  1863,  pag.  51. 


INFLAMMATION    OF   THE   ORBITAL   TISSUES.  193 

uncertain  till  the  opening  of  the  abscess ;  it  may  then  be  made 
positive  by  examination  with  the  sound  and  by  the  character  of 
the  pus,  which,  if  the  bony  walls  of  the  orbit  be  diseased,  has  the 
fetid  smell  and  other  peculiarities  of  bone  pus. 

In  making  the  prognosis,  various  possibilities  are  to  be  remem- 
bered. An  acute  caries  or  necrosis  of  the  superior  orbital  wall 
may  cause  a  fatal  brain  affection;  moreover,  vision  is  greatly 
endangered. 

The  exophthalmns  may  become  so  extreme  that  the  eye  can  no 
longer  be  covered  by  the  lids.  In  consequence  of  this  the  cornea 
becomes  cloudy  and  finally  ulcerates. 

Oftener  the  eye  is  endangered,  not  so  much  by  the  exophthalmus 
as  by  the  inflammatory  process  in  the  orbit.  Blindness  is  gener- 
ally caused  by  neuritis  optica,  in  many  cases,  too,  by  retro-ocular 
neuritis,  which  can  be  recognized  ophthalmoscopically  only  by  its 
final  result, — that  is,  the  atrophic  degeneration  of  the  intraocular 
termination  of  the  optic  nerve. 

Less  frequently,  blindness  is  caused  by  detachment  of  the  retina, 
or  purulent  irido-choroiditis.  Both  complications  may  be  ex- 
plained by  the  communication  which  Schwalbe  has  shown  to  exist 
between  the  space  of  Tenon  and  the  supra-choroidal  lymph-space 
described  by  him. 

The  course  is  generally  acute,  and,  unless  due  to  bone  disease, 
is  ended  in  a  few  weeks;  still,  cases  do  occur  of  chronic  inflam- 
mation of  the  orbital  connective  tissue,  which  go  on  finally  to 
suppuration,  and  which,  extending  through  several  months,  may 
present  the  greatest  diagnostic  difficulties.  In  these  cases,  after 
the  opening  of  the  abscess,  there  often  remains  a  long-persisting 
purulent  discharge,  even  when  no  disease  of  the  bone  exists. 

A  milder  non-purulent  form  of  inflammation  of  the  orbital 
connective  tissue  has  been  described  under  the  name  of  inflamma- 
tion of  the  capsule  of  Tenon ;  this  definition  ought  not  to  be  taken 
too  literally,  since  it  is  not  likely  that  an  inflammatory  process 
which  manifests  itself  by  distinct  symptoms  could  be  limited  to 
the  capsule  of  Tenon  alone  without  involving  the  orbital  con- 
nective tissue.  The  symptoms  are  the  same  as  those  'given 
above,  only  less  severe. 

The  lids  are  either  normal  or  oedematous,  the  conjunctiva,  espe- 
cially in  the  fornix  and  upon  the  sclera,  is  hyperaemic  and  much 


194  INrLAMMATION   OF  THE   ORBITAT^  TISSUES. 

swelled ;  there  is  some  exophthalmus  and  slight  limitation  of 
movements 

The  prognosis  in  the  milder  cases  is  generally  good ;  still,  they 
may  cause  retinal  detachment. 

The  course  is  generally  acute,  but  it  may  become  chronic. 

Treatment. — In  mild  cases  of  inflammation  of  the  orbital  areo- 
lar tissue  it  is  sufficient,  after  a  proper  antiphlogistic  treatment, 
to  use  merely  warm  fomentations  and  the  pressure-bandage. 

If  the  inflammation  be  severe  from  the  beginning,  decided 
antiphlogistic  treatment  is  indicated.  When  it  becomes  probable 
that  the  process  will  go  on  to  suppuration,  that  result  is  to  be 
hastened  by  the  use  of  warm  poultices,  and  the  abscess  should  be 
opened  as  soon  as  fluctuation  can  be  perceived.  Especially  in 
those  cases  where  periostitis  of  the  orbit  is  suspected  must  the 
puncture  be  made  as  soon  as  possible,  in  order  to  prevent  wide- 
spread exposure  of  the  bone. 

The  abscess  is  to  be  kept  open  by  a  charpie  tent,  and,  according 
to  circumstances,  is  to  be  examined  either  immediately  or  some- 
what later  with  the  probe.  In  that  way  the  depth  and  character 
of  the  abscess  and  the  condition  of  the  bony  walls  are  determined. 

It  must,  at  the  same  time,  be  remembered  that  a  foreign  body 
may  remain  a  long  time  in  the  orbit,  and  there  cause  the  forma- 
tion of  an  abscess,  without  the  patient  being  able  to  give  any 
certain  information  respecting  its  presence. 

If  the  cavity  of  the  abscess  be  large,  if  it  has  pockets,  and 
penetrates  behind  the  eyeball,  it  must  be  cleansed  by  frequent 
syringing,  and  must  be  kept  open  till  it  heals  from  the  bottom. 
It  is  advisable  in  these  cases  to  insert  a  drainage-tube  and  thus 
insure  an  easy  escape  for  the  pus.  The  same  practice  is  to  be 
recommended  when  the  bone  is  diseased.  Care  must  be  taken  to 
remove  all  loose  pieces  of  bone. 

Caries  and  necrosis  of  the  orbital  margin  are  most  frequent  on 
the  outer  under  portion,  generally  in  scrofulous  children,  and  in 
the  majority  of  cases  are  due  to  traumatic  causes.  The  portion  of 
the  orbital  margin  in  the  neighborhood  of  the  lachrymal  gland  is 
the  one  next  likely  to  be  diseased. 

Generally,  but  not  always,  a  swelling  develops  above  or  below 
the  external  canthus,  with  reddening  of  the  skin  and  pain ;  this 
gradually  becomes  fluctuating.     The  eyelids  become  swollen  and 


EXOPHTHALMUS    FROM    MORBUS    BASEDOWII.  195 

oedematous;  the  conjunctiva  becomes  inflamed;  slight  fever  be- 
gins; the  abscess  points,  and  finally  breaks.  Nevertheless,  the 
inflammatory  symptoms  of  the  skin  and  conjunctiva  persist;  the 
secretion  of  pus  in  the  cavity  of  the  abscess  continues,  the  open- 
ing becomes  fistulous,  its  edges  uniting  with  the  periosteum,  while 
the  denuded  bone  can  be  felt  with  the  probe.  When  the  swelling 
of  the  lids  has  disappeared,  and  the  skin  is  closely  united  with  the 
periosteum,  portions  of  the  carious  margin  of  the  bone  may  lie 
exposed  to  sight. 

Finally,  the  fascia  tarso-orbitalis,  by  attachment  to  the  diseased 
bony  spot  and  by  ulceration,  becomes  shortened,  and  ectropion  of 
the  lid  is  caused. 

A  similar  form  of  caries  or  necrosis  occurs  in  aged  individuals, 
generally  on  the  upper  orbital  roof.  The  cause  can  seldom  be 
recognized.  It  runs  the  same  course  as  disease  of  the  margin  of 
the  orbit. 

If  such  cases  come  under  treatment  early  enough,  the  abscess  is 
to  be  opened  as  soon  as  possible,  and  as  far  back  from  the  orbital 
margin  as  circumstances  allow. 

EXOPHTHALMUS   FKOM  MOEBUS   BASEDOWII. 

Basedow's  disease  presents  a  group  of  symptoms,  the  principal 
of  which  are  palpitation  of  the  heart,  abnormal  frequency  of  the 
pulse  (100  beats  and  more  per  minute),  swelling  of  the  thyroid 
gland,  and  exophthalmus.  Often,  especially  in  the  beginning  of 
the  disease,  there  are  disturbances  of  digestion,  manifested  by 
frequent  vomiting. 

In  almost  all  cases  the  heart  is  found  to  be  enlarged  and  gen- 
erally dilated,  the  dilatation  being  greatest  in  the  left  ventricle. 
Abnormal  conditions  of  the  valves  have  been  found  in  only  a 
few  cases.  The  hypertrophy  of  the  heart  appears  to  develop  in 
the  course  of  the  disease. 

The  condition  of  the  thyroid  gland  varies  greatly  during  life. 
As  a  rule,  it  is  not  so  much  enlarged  as  in  ordinary  goitre,  and 
still  its  size  is  considerably  increased.  The  most  striking  change 
observed  in  it  is  a  great  development  of  the  vessels,  in  which  a 
diastolic  pulsation  and  murmur  are  frequently  perceptible. 

At  first  there  is  a  simple  swelling  of  the  thyroid  gland.  In 
time  it  may  develop  into  true  goitre,  passing  through  the  various 


196  EXOPHTHALMUS    FROM   MORBUS   BASEDOWII. 

stages  of,  first,  a  uniform  hyperplasia,  then  colloid  and  cystic 
degeneration  or  irregular  fibroid  induration. 

The  cause  of  the  exoplithalmus  is  sometimes  a  hypertrophy  of 
the  fatty  tissues  of  the  orbit,  but  more  frequently  it  is  a  hyper- 
semia  of  these  tissues,  which  can  easily  be  overcome  by  pressure 
during  life,  and  disappears  after  death.*  An  observation  made 
by  Snellenf  shows  enlargement  of  the  orbital  vessels.  He  ob- 
served in  a  case  of  morbus  Basedowii,  while  examining  the  eye 
with  the  stethoscope,  a  distinct  vascular  murmur,  analogous  to 
the  placental  murmur,  but  with  a  slighter  systolic  augmentation. 
Such  murmurs  occur  only  in  places  where  the  blood-channels 
expand,  and,  occurring  in  connection  with  exoplithalmus,  they 
argue  a  distention  of  the  orbital  vessels. 

The  exoplithalmus  is  generally  bilateral  and  symmetrical;  still, 
it  sometimes  happens  that  it  occurs  first  on  one  side,  or,  at  least,  i^ 
greater  on  one  side  than  on  the  other.  It  may  be  very  slight,  or  it 
may  be  so  great  that  the  lids  can  no  longer  be  brought  together. 

A  valuable  diagnostic  sign,  especially  at  the  beginning  of  the 
disease,  is  a  peculiar  disturbance  of  innervation  in  the  upper  lid, 
to  which  attention  was  first  directed  by  Von  Graefe.| 

While  normally  the  upper  lid  accompanies  the  rising  and  fall- 
ing of  the  plane  of  vision,  in  Basedow's  disease  this  movement 
is  lost  or  reduced  to  a  minimum.  Particularly  when  the  cornea 
sinks,  the  upper  lid  fails  to  follow  it.  This  is  not  a  direct  con- 
sequence of  tlie  exophthalmus,  for  with  tumors  of  the  orbit,  or 
other  causes  for  protrusion,  this  symptom  is  often  entirely  absent, 
although  in  extreme  cases  the  movements  of  the  lids  are  naturally 
interfered  with.  But  it  is  present  in  the  slightest  cases  of  exopli- 
thalmus from  Basedow's  disease,  where  the  normal  position  of 
the  eyeball  has  been  but  slightly  altered.  This  symptom  may 
disappear  in  the  course  of  the  disease,  while  the  exoiihthalmus 
continues.  In  one  case  Von  Graefe  saw  a  sudden  disappearance 
of  the  symptom  after  an  injection  of  morphine. 

Von  Stellwag§  calls  attention  to  the  unusual  distention  of  the 


*  Comp.  Virchow,  Die  krankhaften  Gescliwiilste,  B.  iii.  1,  pag.  73- 

f  Arch.  f.  Opbth.,  B.  xvii.  1,  pag.  102. 

j  Deutsche  Klinik,  1864,  No.  16. 

g  Wiener  med.  Jahrbiicher,  ii.  Heft,  1869. 


EXOPHTHALMUS    FROM    MORBUS   BASEDOWII.  197 

palpebral  fissure,  and  to  the  infrequency  and  only  partial  execu- 
tion of  the  involuntary  act  of  winking,  stating  that  these  belong 
to  the  most  frequent  symptoms,  and  referring  them,  as  well  as  the 
defective  associated  movement  of  the  lid,  above  described,  to  dis- 
turbed innervation  in  the  orbicularis  muscle. 

In  favor  of  this  view  we  have  the  circumstance  that  cases  occur 
in  which,  with  loss  of  the  associated  movement  of  the  upper  lid, 
but  with  scarcely  any  perceptible  protrusion  of  the  eye,  the  volun- 
tary closure  of  the  lids  is  accomplished  only  with  the  greatest 
effort:  a  simple  spastic  contraction  of  H.  Miiiler's  smooth  mus- 
cular fibres  of  the  upper  lid  could  oppose  no  very  great  resistance 
to  the  normal  action  of  the  orbicularis. 

The  movements  of  the  eye  are  generally  unobstructed ;  yet  in 
high  degrees  of  exophthalmus  they  may  be  interfered  with  by  the 
stretching  of  the  muscles.  Paralysis  and  fatty  degeneration*  of 
the  ocular  muscles  have  been  observed. 

If  the  exophthalmus  be  so  excessive  that  the  cornea  is  not  covered 
during  sleep,  there  is  danger  of  blindness  being  caused  by  ulcer- 
ation of  the  cornea.  This  serious  result  seems  somewhat  more 
frequent  in  Basedow's  disease  than  in  other  cases  of  chronic  ex- 
ophthalmus. Accordingly,  Von  Graefe  is  inclined  to  regard  the 
corneal  affection  as  possessing  a  neuro-paralytic  character,  and  all 
the  more  since,  in  the  advanced  stages  of  the  disease,  a  diminished 
sensibility  of  the  cornea  is  often  observed. 

The  general  cause  of  all  these  symptoms  must  lie  in  the  ner- 
vous system ;  but  it  cannot  be  said  that  it  has  as  yet  been  certainly 
discovered. 

The  majority  of  cases  occur  in  the  female  sex,  and  develop  gen- 
erally at  the  time  of  puberty,  or  after  confinement.  Prostrating 
sicknesses  have  been  regarded  as  causes  ;  for  instance,  typhus, 
colds  in  the  throat,  and  oftenest  chlorosis.  According  to  Von 
Graefe,  the  disease  occurs  in  men  not  only  less  frequently,  but 
later  in  life,  than  in  women ;  it  also  seems  to  be  more  dangerous. 
Both  blindness  from  corneal  destruction  and  fatal  terminations  of 
the  disease  have  been  observed  much  more  frequently  in  men, 
although  the  disease  is  much  less  frequent  with  them  than  with 
women. 

*  Eecklinghausen,  Deutsche  Klinik,  1863,  No.  29,  pag.  286. 


198  EXOPHTHALMUS   FROM   VENOUS   HYPEREMIA. 

Death  follows  upon  the  increase  of  all  the  symptoms,  sometimes 
very  rapidly,  with  great  anxiety  and  cerebral  disturbances,  but 
generally  gradually,  with  decline  of  nutrition  and  of  the  strength. 
Copious  and  frequently  dysenteric  diarrhoea  and  hemorrhage  from 
the  lungs  are  apt  to  hasten  the  end. 

In  other  cases,  sometimes  after  very  short  duration  of  the  dis- 
ease, recovery  occurs,  or,  at  least,  there  is  such  a  mitigation  of  the 
symptoms  that  they  cause  little  inconvenience. 

Iodine  has  seldom,  but  digitalis  has  often,  proved  useful. 
Tinct.  veratri  viridis  is  recommended,  beginning  with  one  drop 
daily,  and  gradually  increasing;  best  given  in  combination  with 
tinct.  opii,  since  the  veratrum  easily  provokes  diarrhoea  and  vomit- 
ing. Preparations  of  iron,  cold-water  treatment,  sea-bathing,  and 
nutritious  diet  appear  of  the  greatest  use.  The  galvanization 
of  the  sympathetic  nerve  has  also  in  some  cases  appeared  to  be 
beneficial.* 

Corneal  affections  occurring  in  the  course  of  the  disease  require 
atropine  and  the  pressure-bandage. 

In  order  to  diminish  the  gaping  of  the  lids,  Von  Graefef  at 
first  recommended  the  operation  of  tarsorraphy ;  later,  the  partial 
division  of  the  tendon  of  the  levator  palpebrse  superioris. 

EXOPHTHALMUS    FKOM    VENOUS    HYPEREMIA. 

A  similar  form  of  exophthalmus  is  due  to  causes  which  obstruct 
the  flow  of  venous  blood  out  of  the  orbit ;  for  instance,  thrombus 
of  the  ophthalmic  vein,  or  its  compression  by  a  tumor. 

The  causes  of  this  rare  form  of  exophthalmus  cannot  always 
be  determined.  They  are  often  of  a  transitory  nature,  since  the 
affection  sometimes  disappears  in  the  course  of  a  few  months, 
either  spontaneously  or  under  a  nearly  indifferent  treatment. 

Another  group  of  these  cases  presents  the  peculiar  phenomenon 
of  a  pulsating  exophthalmus. 

The  pulsation  in  the  eye,  the  orbit,  and  even  in  the  forehead 
and  temple,  and  the  sound  of  the  accompanying  murmur,  are 
perceptible  to  the  patient,  and  very  annoying  to  him.  The 
protruding  eyeball  may  often  be  gradually  pushed  back  in  the 

*  M.  Meyer,  Berliner  Klinische  Wochenschrift,  1872,  pag.  469. 

t  Arch.  f.  Ophth.,  B.  iii.  2,  pag.  302,  und  Klin.  Monatsbl.,  1867,  pag.  272. 


TUMOES    IN   THE   ORBIT.  199 

orbit,  but  immediately  comes  forward  again  when  tlie  pressure  is 
removed. 

The  anatomical  causes  of  this  pulsating  exophthalmus  may  have 
their  seat  either  within  the  orbit,  or  still  deeper,  within  the  cavity 
of  the  skull. 

Aneurism  of  the  ophthalmic  artery  or  of  its  branches,  or  of  the 
carotis  interna  near  the  sinus  cavernosus,  varicosity  of  the  orbital 
veins,  thrombus  of  the  vena  ophthalmica  or  its  compression  by 
tumors,  have  been  observed  as  causes.  It  is  often  due  to  injuries 
or  to  violent  exertion;  often  no  cause  whatever  is  to  be  discovered. 

Upon  the  assumption  that  the  pulsation  was  caused  by  an  an- 
eurism, the  common  carotid  has  been  tied  a  number  of  times. 
Zehender*  has  collected  31  such  cases,  in  which  23  of  the  opera- 
tions were  followed  by  good  results  and  2  by  death.  The  digital 
compression  of  the  carotid  has  been  made,  sometimes  with  and 
sometimes  without  effect. 

TUMORS    IN    THE    ORBIT. 

Tumors  which  develop  in  the  bottom  of  the  orbit  push  the  eye- 
ball forward,  and  often  at  the  same  time,  according  to  the  form 
and  manner  of  growth  of  the  tumor,  push  it  to  one  side.  Since 
the  exophthalmus  generally  develops  slowly,  the  danger  to  vision 
is  somewhat  less  than  in  the  rapidly-developing  inflammatory 
forms ;  at  least,  the  cornea  is  not  so  much  exposed  to  the  danger 
of  losing  the  protection  of  the  lids,  since  they  frequently  experi- 
ence a  very  considerable  distention.  A  useful  degree  of  vision 
may  therefore  long  be  retained  ;  but  generally  neuritis  or  atrophic 
degeneration  of  the  optic  nerve  is  finally  caused  by  the  irritation, 
compression,  or  distention  to  which  it  is  subjected. 

The  optic  nerve  itself  may  be  the  seat  of  the  tumor,  in  which 
case  there  is  absolute  blindness. 

The  movements  of  the  eye  are  generally  interfered  with,  for  the 
muscles  and  nerves  may  be  compressed  by  the  tumor,  or  may  have 
grown  to  it.  Tiie  eyeball  may  even  be  adherent  to  it,  or  the 
tumor  may  have  grown  into  the  eyeball ;  although  the  reverse 
process  is  more  frequent, — that  is,  the  intraocular  tumor  breaks 
through  the  eyeball  and  extends  into  the  orbit. 

*  Klin.  Monatsbl.,  1868,  pag.  99. 


200  TUMORS    IN    THE    ORBIT. 

It  is  seldom  possible  by  a  clinical  examination  to  satisfy  one's 
self  of  the  nature  of  these  tumors,  since  from  their  position  they 
are  not  accessible  to  direct  examination.  Often  the  only  way  in 
which  the  tumor  can  be  palpated  is  to  thrust  the  little  finger  into 
the  conjunctival  sac,  between  the  lid  and  the  eyeball;  but  even 
then  only  a  small  portion  can  be  reached. 

1^0  symptoms  can  be  named  from  which  the  nature  of  the  tumor 
can  be  determined  with  certainty.  As  the  nearest  approach  to  a 
pathognomonic  symptom,  it  may  be  mentioned  that  sometimes, 
but  not  always,  an  increase  and  decrease  of  the  exophthalmus  have 
been  observed  depending  upon  mechanical  causes  regulating  the 
hyperaeniia  of  the  orbit. 

The  same  symptoms  as  those  caused  by  tumors,  in  the  strict 
sense  of  the  word,  may  be  caused  by  echinococci  or  cysticerci  in 
the  orbit. 

The  diagnosis  of  tumors  which  develop  in  the  anterior  part  of 
the  orbit  is  somewhat  easier.  If  they  extend  behind  the  eyeball 
and  cause  exophthalmus,  it  is  often  impossible  to  determine  how 
far  ba(;kward  the  tumor  extends. 

Orbital  tumors  which  grow  rapidly  should  be  extirpated,  and 
this  course  is  the  more  readily  decided  on  when  sight  has  already 
been  considerably  atlf'ected.  If  the  tumor  be  situated  outside  the 
ocular  muscles,  the  attempt  should  at  least  be  made  to  retain  the 
eyeball.  With  this  object  in  view,  several  of  the  ocular  muscles 
may  be  divided,  the  tumor  enucleated,  and  the  ball  replaced,  the 
muscles  being  again  attached  with  sutures.  If  the  tumor  has 
originally  developed  behind  the  eyeball,  or  if  adhesions  have  been 
formed  between  the  eyeball  and  it,  it  may  be  necessary  to  begin 
the  operation  by  the  enucleation  of  the  eye. 

If  the  malignity  of  the  tumor  be  ascertained,  or  if,  as  is  often 
the  case  with  sarcomatous  growths,  it  has  become  adherent  to  the 
orbital  fasciae  and  periosteum,  it  may  be  necessary  to  remove  even 
the  periosteum  of  the  orbit,  either  as  the  last  act  of  the  operation, 
or  the  tumor  and  periosteum  may  be  removed  at  the  same  time. 

In  general,  after  the  removal  of  these  tumors,  only  a  little  tissue 
remains  in  the  orbit,  and  there  is  no  difficulty  in  pushing  the 
periosteum  back  toward  the  foramen  opticum,  there  as  deep  as 
possible  to  cut  away  it  and  all  the  tissues  included  in  it. 

If  the  removal  of  the  periosteum  has  been  decided  on   before 


HEMORRHAGE    IN    THE    ORBIT,  ETC.  201 

beginning  the  operation,  the  following  is  the  method.  An  incision 
is  made  through  the  skin  around  the  margin  of  the  orbit,  except 
for  a  space  of  about  20  mm.  at  the  inner  angle  of  the  eye,  where 
a  bridge  of  skin  is  left.  A  small  gouge  is  then  used  to  detach 
the  periosteum  from  the  margin  of  the  orbit,  where  it  is  firmly 
adherent.  Farther  back,  where  the  attachment  to  the  bone  is 
looser,  the  handle  of  the  scalpel  may  be  used  for  that  purpose. 
The  entire  mass  enclosed  by  the  periosteum  is  then  cut  throngh  at 
the  apex  of  the  orbit  with  a  pair  of  scissors  curved  on  the  flat ; 
the  mass  thus  loosened  is  drawn  up  out  of  the  orbit  and  reflected 
inward  over  the  nose,  and  then  detached  from  the  inner  surface 
of  the  lids.  Finally,  the  cutaneous  flap  is  turned  back  to  its  place 
and  there  fastened  with  sutures.* 

Bony  tumors  may  grow  from  any  part  of  the  orbital  walls,  but 
are  most  frequent  on  the  upper  and  inner  portion.  These  tumors 
are  often  connected  with  diseased  conditions,  such  as  polypi  or 
granulations  of  the  nasal  cavity  or  frontal  sinus,  or  they  may 
extend  even  into  the  cavity  of  the  skull. f  This  latter  possibility 
is  to  be  particularly  considered  with  reference  to  the  prognosis. 
The  use  of  iodide  of  potassium  has  proved  beneficial  in  many 
cases.  The  resection  of  these  bony  tumors  has  not  generally 
proved  a  satisfactory  operation,  on  account  of  the  uncertainty  in 
the  diagnosis  of  their  nature  and  extent  and  their  inaccessible 
position  in  the  orbit. 

Hemorrhages  in  the  orbit  following  contusions,  cause  exoph- 
thalmus  and  loss  of  motion,  and  in  consequence  of  these  diplopia. 
Diminution  of  vision  also  occurs.  The  ecchymosis  of  the  lids 
and  conjunctiva  confirms  the  diagnosis. 

The  treatment  consists  in  local  blood-letting,  cold  dressings,  and 
the  pressure-bandage. 

Fractures  involving  the  roof  qf  the  orbit  may  cause  fatal  brain 
affections.  If  by  a  fracture  of  the  inner  wall  a  communication 
be  established  between  the  orbit  and  the  nasal  cavity,  emphysema 
of  the  orbit  may  follow. 

Foreign  bodies  may  remain  a  long  time  in  the  orbit  without 
causing  noticeable  symptoms.     Cases  of  this  sort  have  occurred 


*  Snellen  nach  Y.  Langenbeck,  Zevende  Verslag,  1866,  pag.  51. 
t  Comp.  Virchow,  Geschwiilste,  B.  i.  1,  pag.  43. 

14 


202  EXOPHTHALMUS. 

in  which  the  foreign  body  has  been  relatively  large,  such  as  pieces 
•  of  wood,  of  pipe-stem,  etc.  The  manner  in  which  these  injuries 
have  occurred  is  often  such  that  the  patients  are  unable  to  say 
whether  the  foreign  body  which  penetrated  the  orbit,  left  it  again 
or  remained  there.  The  penetrating  substance  may  break  within 
the  orbit,  so  that  fragments  remain  within  which  are  not  visible 
from  without. 

The  wound  in  the  skin  or  conjunctiva  may  close  completely,  or 
it  may  remain  open  and  be  covered  with  granulations.  In  other 
cases  the  injury  is  followed  by  purulent  inflammation  of  the  orbital 
tissues  and  the  discharge  of  pus. 

From  what  has  been  said  it  appears  that  exophthalmus  is  a  symp- 
tom which  may  occur  in  consequence  of  the  most  diverse  diseased 
conditions  of  the  orbit,  and  consequently  may  be  of  all  degrees. 

Recent  investigations  have  shown  that  even  physiologically  the 
position  of  the  eyeball  in  the  orbit  is  not  always  the  same  upon 
the  two  sides.  Frequently  one  eye  lies  some  millimetres  deeper 
than  the  other.  Small  differences  of  position  can  be  determined 
only  by  measurement,  while  greater  ones  cause  a  striking  asym- 
metry of  the  countenance. 

Measurements  to  determine  the  position  of  the  apex  of  the 
cornea  relatively  to  the  margin  of  the  orbit  with  instruments  con- 
structed for  this  purpose  and  called  exojjhthalmometers,  were  first 
made  by  Cohn,*  and  later  by  Hasner,t  Emmert,|  and  Zehender.§ 

*  Klin.  Monatsbl.,  1867,  pag.  339. 

f  Die  StatajDathien  des  Auges,  Prag,  18G9 

X  Klin.  Monatsbl.,  1870,  pag.  33. 

§  Ibid.,  pag.  42. 


DISEASES  OF  THE  LACHRYMAL  APPARATUS. 


Acute  inflammation  of  the  lachrymal  gland  (dacryoadenitis) 
occurs  as  an  inflammation  which  is  localized  in  the  region  of  the 
lachrymal  gland,  and  from  there  spreads  to  the  lids  and  conjunc- 
tiva. The  lids  are  red  and  infiltrated,  so  that  they  can  be  only 
partially  opened  ;  the  conjunctiva  is  hyperaemic  and  swollen  ;  often 
there  is  an  exudation  under  the  conjunctiva  oculi;  generally,  too, 
there  is  an  increased  muco-purulent  secretion. 

We  have,  accordingly,  a  group  of  symptoms  which  occur  also  in 
blennorrlioea,  namely,  a  quickly  developing  inflammatory  swelling 
of  the  lids  and  conjunctiva,  with  muco-purulent  secretion.  It  is, 
however,  easy  to  avoid  mistaking  it  for  blennorrlioea,  since  in  the 
latter  disease  the  mucous  membrane  is  uniformly  aifected  through- 
out its  whole  extent,  while  in  dacryoadenitis  the  inflammation  is 
greatest  in  the  region  of  the  lachrymal  gland  and  diminishes  to- 
ward the  nasal  side.  The  pathognomonic  symptom,  however,  is 
this,  that  the  swollen  lachrymal  gland  pressed  downward  and  out- 
w^ard  can  be  seen  between  the  lid  and  eyeball  when  the  23atient 
looks  downward  and  inward,  while  the  examiner  at  the  same  time 
raises  the  upper  lid  as  much  as  possible.  The  swelling  of  the 
lachrymal  gland  may  be  so  great  that  the  eyeball  is  displaced 
downward  and  inward. 

The  usual  result  is  in  resolution ;  still,  the  connective  tissue  sup- 
porting the  gland,  which  is  the  tissue  essentially  involved  in  the 
inflammation,  may  suppurate  and  a  small  abscess  be  formed,  which 
appears  to  have  more  tendency  to  break  into  the  conjunctival  sac 
than  through  the  skin. 

The  process  appears  also  to  end  sometimes  in  induration  and 
hypertrophy  of  the  gland. 

The  occurrence  of  acute  dacryoadenitis  is  not  very  rare.  Cold 
has  been  regarded  as  the  usual  cause.  Operations  upon  the  eyes 
may  cause  it.* 

*  A.  V.  Graefe,  Arch.  f.  Ophth.,  B.  iv.  2,  pag.  258. 

203 


204  FISTULA   or  THE   LACHRYMAL   GLAND. 

As  to  treatment,  warm  applications  and  protection  from  in- 
jurious influences  are  generally  sufficient.  Under  this  treatment 
recovery  usually  occurs  in  the  course  of  a  few  weeks. 

More  seldom  than  the  acute  form  is  that  which  is  chronic  from 
the  beginning,  which  goes  on  without  external  signs  of  inflamma- 
tion, and  which  often  occurs  on  both  sides.  Iodide  of  potassium 
internally,  or  as  a  salve  applied  in  the  region  of  the  lachrymal 
gland,  has  proved  useful  in  such  cases. 

Fistulas  of  the  lachrymal  gland  are  but  rarely  seen.  They 
may  remain  after  accidental  wounds,  or  after  operations  in  that 
region,  or  may  be  caused  by  ulceration,  as  in  cases  of  lupus. 

So  long  as  the  fistula  remains  open,  the  aqnoyances  are  slight, 
and  consist  principally  in  the  flow  of  tears  from  the  fistulous 
opening.  This  condition  may  remain  a  long  time  unchanged,  but 
it  may  happen  that  the  external  opening  closes  without  the  heal- 
ing of  the  fistulous  canal.  The  secretion  of  the  gland  is  then 
retained,  and  infiltrates  the  surrounding  tissues,  causing  inflamma- 
tion there,  with  swelling  of  the  lids  and  inflammatory  exudation 
beneath  the  conjunctiva  palpebrarum  and  oculi,  often  ending  in 
small  abscesses  of  the  lids. 

Generally  in  the  course  of  the  disease  the  fistula  breaks  open 
again,  the  inflammatory  symptoms  disappear,  but  return  again  if 
the  fistula  closes. 

According  to  Bowman,*  these  fistulas  ai'e  healed  in  the  follow- 
ing manner.  A  strong  silk  thread  is  provided  with  two  needles; 
one  needle  is  passed  into  the  fistulous  opening  and  through  the 
wall  of  the  fistula  and  the  conjunctiva  above  the  tarsus;  the 
second  needle  is  passed  through  in  the  same  way,  but  brought 
through  the  conjunctiva  at  a  distance  of  about  5  mm.  from  the 
first ;  both  ends  of  the  thread  are  then  carried  outward  upon  the 
cheek  and  there  fastened  with  adhesive  plaster.  In  this  way  a 
communication  is  established  between  the  fistula  and  the  con- 
junctival sac,  and  as  soon  as  the  danger  of  inflammatory  reac- 
tion seems  to  be  past,  say  after  from  8  to  14  days,  the  edges  of 
the  external  fistulous  opening  are  to  be  freshened  and  carefully 
united. 

If  the  closure  of  the  external  fistulous  opening  be  effected  in 

*  Ophthalmic  Hospital  Eeports,  i.  pag.  286. 


DACRYOPS.      TUMOK    OF    LACHRYMAL   GLAND.  205 

this  manner,  the  thread  will  finally  cut  its  own  way  through  the 
tissue  included  by  it. 

If  an  old  fistulous  opening  has  become  closed  and  cannot  be 
found,  while  the  patient  is  annoyed  by  oft-returning  inflamma- 
tions, the  only  relief  is  by  extirpation  of  the  lachrymal  gland.* 

Dacryops  is  the  name  given  to  a  rare  tumor  on  the  upper  lid 
near  the  outer  canthus,  which  is  due  to  the  retention  of  the  tears 
in  one  of  the  excretory  ducts  of  the  lachrymal  gland.  It  may 
occur  without  the  actual  closing  of  the  conjunctival  opening  of  the 
duct,  so  that  the  tumor  may  be  emptied  by  pressure.f 

The  tumor  is  distinctly  circumscribed,  very  elastic,  and  pain- 
less ;  the  skin  above  it  is  normal.  Upon  everting  the  upper  lid 
the  tumor  protrudes  in  the  form  of  a  thin-walled  cyst.  What 
characterizes  it  most  is  that  its  size  increases  whenever  increased 
secretion  of  the  lachrymal  gland  occurs. 

The  treatment  of  these  tumors  consists  in  making  an  opening 
into  them  on  the  inner  surface  of  the  lid  large  enough  to  insure 
the  easy  flow  of  the  tears  into  the  conjunctival  sac.  This  is  best 
done  by  passing  a  thread  through  the  conjunctival  wall  of  the 
tumor  in  such  a  way  that  the  puilcture  and  counter-puncture  are 
about  5  mm.  from  each  other.  The  thread  is  then  lightly  tied, 
and  the  two  ends  carried  over  upon  the  cheek  and  there  fastened, 
and  allowed  to  remain  from  8  to  14  days,  till  the  edges  of  the 
wound  in  the  cyst  are  healed. 

Tumors  of  the  lachrymal  gland — simple  hypertrophy,  cystic 
growths,  cancroid,  adenomata,  etc. — cause  in  the  first  place  a  pro- 
trusion of  the  enlarged  gland  between  the  eyeball  and  the  orbital 
wall.  As  the  tumor  grows  and  extends  backward  into  the  orbit 
the  eyeball  is  pressed  forward  and  inward,  and  at  the  same  time, 
according  to  circumstances,  either  upward  or  downward.  With 
this  variety  of  exophthalmus  vision  may  remain  unaffected  a  long 
time,  or  it  may  in  various  ways  be  interfered  with.  If  the  cornea 
be  no  longer  covered  by  the  lids,  the  consequence  will  be  inflam- 
matory clouding,  and  at  last  ulceration  and  rupture,  ending  in 
atrophy  of  the  eye.  Further,  the  mechanical  irritation  of  the 
optic  nerve  may  cause  neuritis.     Finally,  adhesions  may  form 

*  Alfr.  Graefe,  Arch.  f.  Ophth.,  B.  viii.  1,  pag,  279. 
f  A.  V.  Graefe,  Arch.  f.  Ophth.,  B.  vii.  2,  pag.  1. 


206  ANOMALIES    OF   THE    PUXCTA    LACRYMALIA,  ETC. 

between  the  tumor  and  the  eyeball,  and  direct  communications 
between  cysts  of  the  lachrymal  gland  and  the  interior  of  the  eye 
have  been  observed. 

The  extirpation  of  the  lachrymal  gland  with  retention  of  the 
eyeball  is  best  accomplished  by  an  incision  on  the  external  upper 
margin  of  the  orbit,  passing  through  the  skin,  the  muscle,  and 
the  fascia  tarso-orbitalis.  The  length  of  the  incision  is  deter- 
mined by  the  size  of  the  tumor,  and  for  the  normal  gland  should 
be  about  25  mm.  The  eyeball,  when  necessary,  should  be  pro- 
tected by  a  horn  si)atula  thrust  under  the  upper  lid,  the  gland 
seized  with  the  toothed  forceps,  and  then  detached  first  from  the 
periosteum  and  then  from  the  surrounding  soft  parts.  The  last 
act,  especially  in  the  case  of  the  normal  gland,  is  difficult,  by  reason 
of  the  toughness  of  the  tissues  and  the  copious  hemorrhage. 

The  wound  under  the  use  of  ice-dressings  may  heal  quickly, 
but  suppuration  as  well  as  erysipelatous  inflamuiation,  with  great 
swelling  of  the  lids,  fever,  and  symptoms  of  cerebral  hypersemia, 
may  follow. 

The  function  of  the  eye  is  not  essentially  interfered  with  by 
the  extirpation  of  the  lachrymal  gland. 

ANOMALIES    OF    THE    PUNCTA    LACRYMALIA    AND    CANALICULI. 

The  congenital  anomalies  of  these  organs  are  their  occlusion 
and  their  presence  in  superfluous  number. 

Foreign  bodies  which  accidentally  enter  them,  such  as  hairs, 
eyelashes,  etc.,  may  close  the  canals,  and  at  the  same  time  provoke 
inflammatory  symptoms. 

Cryptogamous  growths  (leptothrix)  must  be  included  among 
the  foreign  bodies  found  in  the  canaliculi.  They  have  been 
observed  oftener  in  the  lower  than  in  the  upper  canaliculus,  and 
may  fill  it  so  completely  as  to  cause  a  perceptible  tumor.  The 
neighboring  tissues  become  inflamed,  the  caruncle  and  adjacent 
conjunctiva  are  reddened,  the  edges  of  the  lids  corresponding  to 
these  [)arts  are  swollen,  the  lower  punctum  is  enlarged,  and  often 
discharges  a  white  secretion,  especially  on  pressure.  In  this  con- 
dition a  troul>lesome  dripping  of  the  tears  occurs.  In  the  further 
course  of  the  affection  the  local  inflammation  and  swelling  in- 
crease, exciting  from  time  to  time  diffuse  catarrh  of  the  conjunc- 
tiva.    After  splitting  up  the  canaliculus  the  concretions  may  be 


ANOMALIES   OF   THE    PUNCTA    LACRYMALIA,  ETC.  207 

pressed  out,  and  consist  of  leptothrix-eleraents  often  mixed  with 
the  salts  of  lime.  The  treatment  consists  in  splitting  and  carefully 
cleansing  the  canaliculi. 

An  abnormal  position  of  the  lower  punctum  occurs  in  conse- 
quence of  chronic  inflammatory  swelling  of  the  conjunctiva,  or  of 
those  superficial  contractions  of  the  skin  which  result  from  chronic 
blepharitis.  It  is  in  fact  a  slight  ectropion,  which  is  most  ap- 
parent when  the  patient  looks  upward,  since  in  that  position  the 
lower  lid  is  raised  slightly  away  from  the  eye.  In  consequence 
of  its  abnormal  position  the  lower  punctum  cannot  receive  the 
tears,  but  they  collect  at  the  inner  angle  of  the  lids  and  trickle 
down  the  cheek.  In  this  condition  the  puncta  themselves  may 
be  unchanged,  or,  especially  in  chronic  blepharitis,  they  may  be- 
come obliterated  and  entirely  disappear.  The  small  prominences 
on  which  they  stand  become  levelled  down,  that  part  of  the  edge 
of  the  lid  rounded  off,  the  puncta  greatly  contracted,  so  that  it 
becomes  difficult  or  impossible  to  find  them.  To  cure  these  cases, 
Bowman  has  proposed  the  splitting  of  the  canaliculi,  thus  con- 
verting them  into  open  furrows  upon  the  conjunctival  surface. 
To  do  this  the  punctum  is  first  dilated  by  a  probe  whose  fine  point 
thickens  rapidly,  and  room  is  thus  made  in  which  to  introduce 
Weber's  knife;  this  consists  of  a  probe-pointed  sound,  which  about 
2  mm.  back  from  its  blunt  point  passes  over  into  a  small  convex 
blade,  about  1^  or  2  mm.  wide.  The  point  is  thrust  into  the  lach- 
rymal sac,  and  the  canaliculus  is  split  by  lifting  the  handle  in  the 
case  of  the  lower,  or  depressing  it  in  the  case  of  the  upper  canalic- 
ulus. To  avoid  reunion  of  the  edges  of  the  wound,  it  is  well  to 
keep  the  patient  several  days  under  observation,  and  to  break  up 
with  a  fine  sound  any  adhesions  which  may  occur.  This  practice 
is  generally  successful,  and  yet  in  cases  of  chronic  blejiharitis  it 
sometimes  fails  in  spite  of  all  pains  taken  ;  and  even  without  this 
complication  it  sometimes  happens  that  the  canaliculi,  which  have 
been  split  and  kept  open  for  months,  finally  reunite  throughout 
their  entire  length. 

Wounds  which  have  divided  the  canaliculi  should  be  carefully 
united  by  sutures  and  then  kept  in  perfect  rest.  If  cicatrization 
destroy  the  continuity  of  the  canal,  it  generally  is  not  possible  to- 
re-establish it  again. 

In  consequence  of  such  wounds,  or  of  ruptures  of  the  lachrymal 


208  DISEASES   OF   THE   LACHEYMAL   SAC. 

sac  by  contusions,  air  may  be  driven  from  the  nasal  cavity  through 
the  canaliculus  into  the  subcutaneous  connective  tissue,  for  instance, 
during  forced  expiration,  sneezing,  etc.  Its  presence  there  is  de- 
tected by  a  crepitating,  emphysematous  tumor.  At  the  same  time 
infiltration  of  the  tears  into  the  tissues  of  the  lids  may  take  place. 

DISEASES   OF   THE   LACHRYMAL   SAC. 

The  first  symptom  of  acute  dacryocystitis  is  generally  a  consider- 
able swelling  of  the  mucous  membrane  of  the  lachrymal  sac,  both 
painful  and  tender,  and  causing  a  low,  rounded,  circumscribed 
tumor.  The  skin  lying  over  it  is  generally  red  and  swollen  from 
the  first.  The  inflammation  involves  the  inner  angle  of  the  eye, 
so  that  the  lids,  the  caruncle,  and  often,  too,  the  conjunctiva  pal- 
pebrarum, are  oedematous.  The  swelling  and  redness  frequently 
spread  out  upon  the  nose  and  cheek.  Generally  the  inflammation 
goes  on  to  suppuration  within  the  sac,  and  rupture  outwards;  still, 
resolution  may  occur,  or  the  dacryocystitis  become  chronic. 

It  is  generally  due  to  strictures  in  the  nasal  duct,  which  cause 
retention  of  the  secretion,  and  consequent  inflammatory  changes 
in  the  mucous  membrane.  Under  these  circumstances  accidental 
causes,  such  as  cold,  may  excite  acute  inflammation,  or  an  in- 
flammation which  was  at  first  slight,  may  cause  such  a  rapid 
accumulation  of  the  secretions  that  the  distention  of  the  sac 
excites  inflammation  in  the  adjoining  tissues. 

It  is  best  from  the  beginning  to  use  warm  cataplasms:  the 
tension  of  the  tissues  is  thereby  diminished,  the  pain  soothed,  and 
resolution,  if  possible  for  it  to  occur,  is  favored.  If  the  inflam- 
mation go  on  to  suppuration  the  tumor  points,  becomes  soft  and 
fluctuating,  and  the  pus  can  be  seen  through  the  skin.  Under 
these  circumstances  the  cataplasms  may  be  continued,  and  the 
spontaneous  opening  of  the  tumor  awaited,  or  it  may  be  incised, — 
and  this  is  generally  most  advantageous,  since  in  this  way  the  sac 
is  more  freely  evacuated.  After  opening  the  sac  it  is  advisable,  in 
order  to  avoid  too  speedy  closure,  to  place  charpie  in  the  wound; 
and  under  all  circumstances  the  free  discharge  of  the  secretions 
must  be  insured  by  the  use  of  cataplasms  and  frequent  syringing 
with  warm  water.  The  opening  must  not  be  allowed  to  heal  till 
the  swelling  of  the  mucous  membrane  is  so  far  reduced  that  the 
secretions  can  be  discharged  through  the  normal  channels, — that 


DISEASES    OF   THE    LACHRYMAL   SAC.  209 

is,  through  the  nasal  duct  and  canaliculi.  Exceptionally  the 
opening  shows  no  tendency  to  heal,  so  that  a  lachrymal  fistula  is 
formed.  But  no  matter  what  course  the  dacryocystitis  takes, 
whether  it  end  in  resolution,  suppuration,  chronic  inflammation, 
or  fistula,  the  second  steji  always  consists  in  determining  whether 
there  are  strictures  in  the  nasal  duct,  and,  if  they  are  found, 
proceeding  to  their  treatment. 

Chronic  inflammation  of  the  mucous  membrane  of  the  lachry- 
mal sac  (blennorrhoea  sacci  lacrymalis)  develops,  as  does  the  acute 
form,  almost  always  from  the  presence  of  strictures. 

Since  the  normal  force  which  impels  the  tears  through  the  nasal 
duct  is  but  very  slight,  a  moderate  contraction  of  this  passage  suf- 
fices to  cause  above  the  stricture  an  accumulation  of  the  secretions; 
this  decomposes  and  irritates  the  mucous  membrane.  The  irritated 
membrane  contributes  now,  on  its  part,  to  the  increase  of  the 
secretion,  that  portion  of  the  canal  above  the  stricture  becomes 
filled,  and  the  membranous  walls  of  the  lachrymal  sac,  which, 
from  the  chronic  inflammation  and  infiltration  of  the  mucous  mem- 
brane and  adjacent  tissues,  have  become  relaxed,  yield  gradually 
to  the  pressure  of  the  accumulating  secretion. 

The  distended  sac  now  causes  at  the  nasal  angle  a  small  tumor, 
whose  muco-purulent  contents  may  be  discharged  by  pressure  of 
the  finger  either  downward  into  the  nasal  cavity  or  upward 
through  the  canaliculi.  This  condition  may  remain  for  a  long 
time  unchanged,  without  any  exterual  visible  signs  of  inflamma#ion : 
or  the  relaxation  and  distention  of  the  sac  may  increase,  and  the 
tumor  enlarge  till  it  attains  the  size  of  a  cherry-stone  or  hazel-nut; 
it  may  even  become  larger,  and  in  such  cases  the  contents  gener- 
ally lose  their  purulent  character,  changing  to  an  almost  colorless, 
clear,  thin  mucus  (atonia  or  hydrops  sacci  lacrymalis).  In  other 
cases  external  signs  of  inflammation  are  superadded,  and  these  run 
a  course  similar  to  that  of  acute  dacryocystitis,  or  they  may  con- 
tinue for  a  long  time  in  a  subacute  course,  and  may  even  finally 
lead  to  rupture  of  the  sac.  In  such  cases  the  contents  do  not 
always  reach  the  surface  by  the  shortest  way;  the  pus  breaks  from 
the  sac  into  the  adjoining  tissue  and  there  spreads  out  irregularly, 
often  in  several  channels,  before  it  penetrates  the  skin. 

The  etiology  is  generally  the  same  as  in  acute  dacryocystitis. 
Strictures  are  almost  always  present.     Still,  it  may  be  caused  by 


210  STRICTURES   OF   THE   NASAL   DUCT. 

foreign  bodies  in  the  nose,  nasal  polypi,  or  by  the  necrosis  of  the 
surrounding  bones,  due  to  scrofula  or  syphilis. 

The  treatment  as  regards  acute  exacerbations  is  the  same  as  in 
the  acute  form.  In  most  of  these  chronic  cases  the  cure  of  the 
stricture  is  the  first  indication. 

Strictures  of  the  nasal  duct  are  most  frequent  at  its  lower  ex- 
tremity, and  just  below  the  sac,  at  the  boundary  between  the 
orbital  and  maxillary  parts.  These  strictures  are  often  due  to 
chronic  catarrhal  inflammation,  which  is  frequently  connected 
with  diseases  of  the  nasal  raucous  membrane. 

In  consequence  of  this  connection,  scrofula  may  be  classed 
among  the  causes.  Acute  blennorrhoeal  inflammation  of  the  con- 
junctiva causes  frequently  a  similar  inflammation  of  the  mucous 
membrane  of  the  tear-passages,  probably  because  the  resorption 
of  the  tears  is  prevented  at  the  most  infectious  period  of  the  blen- 
norrhcea,  by  the  swelling  of  the  conjunctiva.  Chronic  conjunc- 
tival inflammations  appear  more  likely  to  cause  strictures.  In 
many  cases  it  is  not  possible  to  discover  any  cause. 

The  contraction  of  the  duct,  of  course,  j^resents  a  hindrance  to 
the  passage  of  the  tears,  but  this  does  not  always  cause  permanent 
epiphora.  It  is  not  rare  to  see  persons  whose  nasal  ducts  are 
almost  closed,  and  who  yet  are  but  little  discommoded  by  the  tears, 
— never,  indeed,  except  under  circumstances  which  cause  increased 
secretion,  as,  for  instance,  slight  conjunctivitis.  In  such  cases, 
without  touching  the  stricture,  the  difficulty  may  often  be  relieved 
by  the  use  of  some  mild  astringent  eye- water, — for  instance,  a  ^ 
per  cent,  solution  of  sulphate  of  zinc. 

In  most  cases,  however,  the  strictures  appear  to  lead  to  the 
above-described  blennorrhoeal  condition  of  the  tear-passages. 

The  treatment  of  the  strictures  is  best  accomplished  by  the 
introduction  of  Bowman's  probes,  which  may  be  curved  so  as  to 
adapt  themselves  to  the  anatomical  relations  of  the  special  cases. 
Generally  a  circular  curvature,  with  a  radius  of  from  40  to  50 
mm.,  is  most  suitable. 

After  one  of  the  canaliculi — for  instance,  the  lower  one — has 
been  split  up  in  the  manner  above  described,  and  the  bleeding 
has  stopped,  the  sound  is  slipped  along  the  lower  anterior  wall 
of  the  canal  into  the  sac.  While  doing  this,  the  punctum  lacry- 
male  must  be  (Jrawu  somewhat  outward  and  downward,  and  the 


PEOBING   THE    NASAL,    DUCT.  211 

canaliculus  held  tense  in  that  direction,  while  the  patient  is  told  to 
look  upward.  The  probe  is  carefully  thrust  forward,  in  a  nearly 
horizontal  direction,  until  its  end  strikes  the  median  wall  of  the  sac, 
resting  against  the  lachrymal  bone.  Then  the  probe  is  brought  into 
a  nearly  vertical  position.  If  during  the  passage  of  the  probe 
through  the  canal,  or  the  attempt  to  turn  it  up  in  the  vertical 
position,  its  end  is  seen  to  cause  tension  on  the  lid,  that  is  proof 
that  it  has  not  yet  entered  the  sac,  but  that  it  has  caught  in  the 
canaliculus. 

In  introducing  the  probe  through  the  upper  canaliculus,  it  is  to 
be  slid  along  the  median  wall  down  into  the  lachrymal  sac. 

In  general,  while  introducing  the  probe,  its  direction  at  any 
given  time  should  correspond  with  the  direction  of  that  portion 
of  the  tear-passage  through  which  the  point  of  the  probe  is  then 
passing.  While  the  sound  is  gliding  down  the  nasal  duct  the 
upper  part  of  the  sound  should  lie  in  contact  with  the  upper  eye- 
brow, from  4  to  6  mm.  to  the  median  side  of  the  incisura  supra- 
orbitalis.  Under  all  circumstances,  tlie  operator  must  proceed 
carefully,  without  the  use  of  force,  and  find  his  way  through  the 
stricture  by  a  rotary  motion  of  the  probe.  Sometimes  there  are 
pockets  above  the  stricture,  especially  in  the  outer  anterior  wall  of 
the  sac;  the  probe  may  easily  be  passed  into  one  of  these,  and  its 
■farther  progress  absolutely  prevented.  When  this  occurs,  instead 
of  using  force,  the  probe  must  be  withdrawn  a  little  distance,  and 
the  normal  passage  sought,  while  avoiding  the  diverticulum.  By 
proper  manipulation  of  the  probe  the  stricture  may  almost  always 
be  passed,  and  I  recall  but  few  cases  in  which  an  absolutely  im- 
permeable stricture  seemed  to  exist.  I  have  satisfied  myself  by 
anatomical  examination  that  such  complete  strictures  do,  however, 
occur.  In  one  case,*  for  instance,  I  found  the  lachrymal  sac  con- 
siderably distended,  filled  with  viscid  mucus,  the  mucous  membrane 
smooth,  and  the  lower  end  of  the  sac  absolutely  closed  by  cicd,- 
tricial  tissue:  the  lower  end  of  the  nasal  duct  was  also  closed  by 
the  same  tough  tissue.  Within  the  duct  thus  closed  on  every  side 
I  found  a  transparent  viscid  secretion,  which  was  mixed  with 
numerous  epithelial  cells  (perhaps  a  post-mortem  occurrence),  and 
was  coagulable  with  acetic  acid. 

*  Verhandl.  cler  physical. -med.  Gesellschaft  zu  Wiirzburg,  B.  x.  pag.  12. 


212  PEOBING   THE    NASAL    DUCT. 

Complete  stricture  ought  not  to  be  assumed  simply  because  the 
probe  cannot  be  passed  at  the  first  sitting.  The  splitting  of  the 
canaliculi,  the  easier  and  more  frequent  discharge  of  the  secretion, 
and  the  syringing  with  some  astringent  solution,  in  many  cases 
cause,  in  the  course  of  some  days,  a  diminution  in  the  swelling 
of  the  mucous  membrane,  so  that  the  probe  can  be  passed  without 
any  trouble.  The  probe  is  allowed  to  remain  in  the  canal  for  a 
quarter  or  half  an  hour,  and  is  then  carefully  and  slowly  with- 
drawn. The  probing  is  generally  repeated  every  day ;  but  if  it 
be  very  painful,  or  if,  after  the  withdrawal  of  the  probe,  there  be 
hemorrhage  from  the  nose,  it  is  well  to  wait  some  days  before 
repeating  the  operation. 

It  is  best  to  begin  with  a  probe  having  a  diameter  of  about  1 
mm.,  and  increase  gradually  to  those  with  a  diameter  of  1.5  or 
1.75  mm.  The  probes  first  introduced  by  Bowman  have  as  their 
highest  numbers  some  of  greater  thickness,  but  Arlt  very  properly 
warns  against  the  use  of  too  thick  a  probe.*  The  observation 
that  stricture  of  the  canaliculi  at  their  place  of  opening  into  the 
lachrymal  sac  may  be  a  consequence  of  probing,  has  been  often 
enough  made,  and  Arlt  explains  it  by  saying  that  in  these  cases 
this  place  has  been  wounded  by  too  thick  a  probe.  This  reason 
applies  with  still  greater  force  against  the  use  of  A.  Weber's 
probes,  which  at  the  point  corresponding  with  the  openings  of 
the  canaliculi  into  the  sac  have  a  diameter  of  at  least  2  mm.,  and 
the  highest  a  diameter  of  3  or  4  mm.  Weber,  indeed,  recom- 
mends that  the  canaliculi  be  split  through  their  whole  extent 
down  to  the  sac,  involving  the  incision  of  the  ligamentum 
mediale ;  but  it  is  very  doubtful  if  by  this  method  the  mechan- 
ical irritation  is  lessened.  Arlt  suggests  further  that  similar 
contractions  may  occur  also  at  the  lower  end  of  the  nasal  duct 
in  consequence  of  using  too  thick  a  probe.  Certainly  it  is  as 
likely  to  occur  here  as  in  the  canaliculi,  for  the  anatomical  rela- 
tions at  this  point  present  the  greatest  variations.  "  In  many 
cases  the  mucous  membrane  forms  here  simply  a  covering  for  the 
bony  walls ;  the  nasal  opening  will  then  be  wide  and  round,  with 
sharp  margins.     If  the   canal  continue  a   distance   within   the 


*  Behandlung  der  Thranenschlauchkrankheiten,  Arch.  f.  Opth.,  B.  xiv. 
3,  pag.  270. 


PROBING   THE    NASAL    DUCT.  213 

mucous  membrane  on  the  side  of  the  nasal  cavity,  its  opening 
is  sometimes  narrow,  sometimes  wide,  sometimes  round,  some- 
times a  mere  slit,  which  is  sometimes  horizontal,  sometimes  ver- 
tical. In  general,  the  deeper  the  opening  the  narrower  it  is. 
Frequently  one  seeks  in  vain  for  it,  even  after  removal  of  the 
palate,  when  the  light  is  allowed  to  fall  into  the  space  covered 
by  the  turbinated  bone,  and  it  can  be  found  only  by  passing  a 
fine  bristle,  or  making  an  injection  from  the  lachrymal  sac 
downward."* 

In  undertaking  the  treatment  by  probing,  it  is  impossible  to 
tell  which  of  these  anatomical  variations  exists,  but  it  will  do  no 
harm  to  assume  in  every  case  that  the  most  unfavorable  condi- 
tion exists,  and  therefore  proceed  to  probing  in  the  most  careful 
manner. 

It  is  well  from  time  to  time,  during  the  treatment  by  probing, 
to  try  whether  the  duct  is  permeable  also  for  injections.  Cases 
occur  in  which  the  probe  passes  easily,  while  an  injection  will 
not ;  the  point  of  the  canula  must  first  be  passed  through  the 
stricture.  The  canula  must,  of  course,  have  the  size  and  curva- 
ture of  a  Bowman's  probe.  It  is  not  strange  that  in  such  cases 
the  epiphora  continues,  although  the  probe  passes  easily. 

But  even  when  both  probes  and  injections  pass  easily,  the 
epiphora  may  continue  in  consequence  of  the  distention  and  re- 
laxation of  the  lachrymal  sac,  since,  probably,  an  elastic  tension 
of  its  walls  is  necessary  to  cause  a  normal  discharge  of  the  tears. 
One  often  sees,  in  persons  with  a  loose  texture  of  the  entire  lids, 
an  already  existing  slight  epiphora  increase  under  the  influence 
of  a  mild  conjunctivitis,  in  spite  of  the  permeability  of  the  nasal 
duct.  In  such  cases  less  is  accomplished  by  continuous  probing 
than  by  the  local  treatment  of  the  conjunctiva  and  mucous  mem- 
brane of  the  sac.  In  a  series  of  similar  cases  Alfr.  Graefef  has 
shown  the  cause  of  the  epiphora  to  be  a  hypertrophy  of  the  lach- 
rymal caruncle,  and  by  its  extirpation  he  removed  the  difiQculty. 
Nasal  polypi  may  cause  epiphora  in  a  similar  manner. 

While  the  strictures  are  being  probed,  attention  is  to  be  di- 

*  Henle,  Anatomie,  B.  ii.  pag.  712.  Comp.  K.  Maier,  IJeber  den  Bau  der 
Thranfnorgane,  pag.  20,  Freiburg,  1869. 

f  Klinische  Monatsblatter  f.  Augenheilk.,  1868,  pag.  223. 


214  TREATMENT   OF   LACHRYMAL   DISEASES. 

rected  at  the  same  time  to  the  secondary  inflammatory  processes 
caused  by  them.  Chronic  conjunctivitis  and  blepharitis  are  here 
first  to  be  mentioned.  The  first  requires  the  use  of  a  strong 
astringent  solution  of  nitrate  of  silver  (1  or  2  per  cent.),  or  of 
sulphate  of  zinc  (2  or  3  per  cent.),  which  is  to  be  pencilled  on  the 
lids,  and  then  immediately  washed  away  with  water.  To  cure 
the  blepharitis,  which  is  maintained  by  the  presence  of  small 
ulcers  on  the  edges  of  the  lids,  it  is  necessary  in  the  first  place 
carefully  to  remove  the  crusts  which  cover  these  ulcers,  and  then 
pencil  thera  with  some  solution  which  will  cause  a  slight  eschar; 
for  instance,  nitrate  of  silver  (3  per  cent.)  or  acetate  of  lead,  or  a 
concentrated  solution  of  sulphate  of  copper,  or,  finally,  a  salve  of 
precipitate  of  mercury,  1  to  2  per  cent.,  in  ung,  glycerin i.     • 

More  important  still  is  the  treatment  of  the  mucous  membrane 
of  the  lachrymal  sac,  when  that  throws  off  a  blennorrhoeal  secre- 
tion; indeed,  in  many  cases,  upon  this  depends  the  relief  of  the 
principal  annoyances  of  which  the  patients  complain.  In  mild 
cases  it  often  suffices  to  press  out  the  secretion  and  inject  an 
astringent  solution  of  ^  per  cent,  nitrate  of  silver,  or  sulphate 
of  copper  or  of  zinc,  etc.  The  injections  must  always  be  very 
carefully  made,  since,  if  the  mucous  membrane  of  the  canal  be 
wounded,  the  fluid  may  be  driven  into  the  subcutaneous  tissue  of 
the  lids,  and  even  into  the  orbit,  and  there  excite  violent  inflam- 
mation. If  the  secretion  be  copious  and  the  sac  greatly  distended, 
it  is  best  to  make  an  incision  into  it,  and  in  this  way  open  a  direct 
passage  into  the  mucous  membrane.  The  opening  must  be  made 
large  enough  to  allow  the  introduction  of  a  pencil  of  pure  or  miti- 
gated (^  or  ^  nitrate  of  potassium)  nitrate  of  silver,  with  which 
to  cauterize  the  interior  of  the  sac.  To  neutralize  the  superfluous 
nitrate  of  silver,  a  solution  of  common  salt  is  to  be  applied  with 
a.  camel-hair  pencil.  The  wound  is  to  be  kept  open  by  a  piece  of 
catgut  so  long  as  it  is  wished  to  continue  the  cauterization  of  the 
mucous  membrane. 

When  the  sac  is  very  greatly  distended.  Bowman  has  recom- 
mended to  excise  a  portion  of  its  anterior  wall. 

The  undeniable  fact  that  strictures  of  the  lachrymal  duct,  after 
satisfactory  treatment  by  probing,  often  return,  has  led  to  many 
attempts  to  modify  that  method. 

In  the  first  place  it  was  undertaken  by  using  the  thickest  pos- 


TREATMENT   OF    LACHRYMAL   DISEASES.  215 

sible  probes,  or  expansible  laminaria  bougies,  to  dilate  the  stric- 
ture as  far  as  the  diameter  of  the  lachrymal  duct  would  allow. 
We  have  already  stated  the  objections  to  this  practice. 

In  order  to  avoid  the  daily  introduction  of  the  probe,  Walton* 
proposed  to  use  a  style  which  could  be  allowed  to  remain  a  longer 
time.  Williamsf  also  favors  this  method.  So  soon  as  Bowman's 
probe  can  be  allowed  to  remain  inserted  for  say  half  an  hour 
without  annoyance,  it  may  generally  be  assumed  that  a  style  made 
for  the  purpose  can  be  worn  for  a  still  longer  time.  This  practice 
commends  itself  for  such  patients  as  are  unable  to  present  them- 
selves for  treatment  by  probing  as  often  as  is  desirable. 

Finally,  JaescheJ  and  Stilling§  have  proposed  to  cut  through 
the  strictures.  According  to  both  their  methods  the  cutting  in- 
strument is  to  be  introduced  through  one  of  the  canaliculi,  which 
can  hardly  be  done  without  at  the  same  time  wounding  its  walls. 

I  have  therefore  preferred,  in  some  cases  which  I  have  treated 
in  this  manner,  to  open  the  lachrymal  sac,  since  a  simple  incision 
in  its  walls  can  always  be  made  to  heal,  while  the  introduction  of 
the  instrument  through  the  canaliculi  causes  injuries  which  may 
lead  to  their  entire  obliteration.  After  opening  the  sac,  Weber's 
knife,  either  alone  or  upon  a  director,  was  passed  through  the 
stricture,  which  was  incised  in  several  different  places  by  up-and- 
down  cuts  with  the  knife. 

Whether  strictures  return  less  frequently  after  incision  than 
after  probing,  remains  yet  to  be  determined. 

The  former  much-employed  practice  of  obliterating  the  lachry- 
mal sac  is  not  often  indicated.  It  is  called  for  only  where  an  in- 
curable blennorrhoea  exists  above  an  impermeable  stricture  of  the 
canal.  To  do  the  operation,  the  wall  of  the  sac  is  split  as  widely 
as  possible,  the  wound  still  further  enlarged  by  sponge  tents,  and 
the  attempt  made  to  destroy  the  mucous  membrane  by  caustics 
or  the  actual  cautery.  Various  caustics  have  been  recommended, 
the  concentrated   mineral  acids,  chloride  of  zinc,  etc.     But  the 

*  British  Medical  Journal,  1863,  April. 

f  Annales  d'Oculistique,  9.  ser.,  iii.  pag.  86,  and  Arch.  f.  Augen-  und 
Ohrenheilkunde  von  Knapp  und  Moos,  B.  i.  pag.  78. 

X  Arch.  f.  Ophth.,  1864,  B.  x.  2,  pag.  166. 

§  Ueber  die  Heilung  der  Verengerung  der  Thranenwege  mittelst  der  inneren 
Incision,  CasscJ,  1868. 


216  TREATMENT    OF    LACHRYMAL,    DISEASES. 

best  method  is  tlie  use  of  nitrate  of  silver,  to  be  neutralized  im- 
mediately after  with  a  sohition  of  common  salt.  By  this  method 
one  can  be  certain  that  the  cauterization  is  localized  and  is  not 
infiltrated  in  the  adjoining  tissues.  Energetic  cauterizations  must 
be  made  daily  for  some  time  in  order  gradually  to  destroy  the 
mucous  membrane.  Care  must  be  taken,  too,  that  the  concen- 
trated solution  of  silver  which  forms  in  the  sac  during  the  cauter- 
ization does  not  run  through  the  canaliculi  into  the  conjunctival  sac. 

If  one  wish  to  employ  the  actual  cautery  for  the  obliteration 
of  the  lachrymal  sac,  the  galvano-caustic  is  the  best. 

An  annoying  epiphora  does  not  always  remain  after  obliteration 
of  the  sac,  just  as  strictures  may  exist  without  giving  rise  to  any 
great  inconvenience,  provided  they  do  not  cause  a  blennorrhoeal 
inflammation  of  the  mucous  membrane. 

If  rupture  of  the  lachrymal  sac  occur  in  chronic  dacryocystitis, 
the  opening  generally  closes  under  proper  treatment,  or  perhaps 
spontaneously.  Often,  however,  it  sliows  no  tendency  to  heal ;  it 
contracts  only  slightly,  the  edges  become  callous,  and  a  lachrymal 
fistula  is  established,  out  of  which  ])us  and  tears  flow.  Especially 
is  this  the  case  when  from  syphilis,  scrofula,  or  any  other  cause 
there  is  caries  of  the  bony  walls  of  the  lachrymal  canal.  But 
fistulas  of  the  lachrymal  sac  occur  also  without  any  disease  of 
the  bone.  In  many  cases  the  opening  becomes  exceedingly  small, 
and  if  at  the  same  time  no  blennorrhcea  of  the  sac  exist,  or  very 
little,  the  annoyance  is  very  slight. 

The  first  object  of  treatment  is  to  re-establish  the  normal  passage 
through  the  nasal  duct.  The  presence  of  bone  disease  demands, 
besides  the  local  treatment  of  tlie  diseased  bone,  of  the  mucous 
membrane,  and  of  the  strictures,  treatment  of  the  existing  dys- 
crasia.  Especially  is  the  use  of  iodide  of  potassium  often  indicated 
in  these  cases. 

If  there  be  no  bone  disease,  it  is  well,  in  addition  to  the  probing, 
to  touch  the  walls  of  the  fistula  with  nitrate  of  silver.  If  the 
duct  below  the  fistula  be  obliterated,  and  if  there  be  considerable 
blennorrhcea  of  the  mucous  membrane,  the  question  of  the  cauter- 
ization of  the  sac  arises.  Capillary  fistulas  are  best  left  untouched, 
since  when  there  is  absolute  impermeability  of  the  lachrymal  canal 
the  closure  of  the  fistula  will  probably  not  improve  the  condition. 

Spontaneous  obliteration  of  the  lachrymal  sac  occurs  quite  rarely 


POLYPI  OF  THE  LACHRYMAL  SAC.  217 

in  consequence  of  dacryocystitis.    Sometimes  when  this  occurs  the 
fossa  lacrymalis  may  be  seen  externally. 

Polypi  of  the  lachrymal  sac  occur  simultaneously  with  the  blen- 
norrhoea  of  its  mucous  membrane.  Their  presence  may,  in  many 
cases,  be  recognized  by  the  fact  that  after  pressing  out  the  blen- 
norrhceal  secretion  through  the  puncta,  the  sac  is  not  emptied, 
but  still  offers  an  elastic  resistance.  There  is  no  difficulty  in  ex- 
tirpating these  polypi  after  opening  the  sac.  But  such  growths 
sometimes  occur  also  in  the  lower  part  of  the  nasal  duct.  I  have 
at  least  once  during  an  anatomical  examination  found  a  pedicu- 
lated  villous  growth  of  the  mucous  membrane  in  the  lower  third 
of  the  duct.*  In  such  cases  both  the  diagnosis  and  the  treatment 
would  be  very  difficult. 

*  Verhandlungen  der  medicinisch-physikalischen  Gesellschaft  zu  Wiirz- 
burg,  B.  10,  pag.  xii. 


15 


DISEASES  OF  THE  EYELIDS. 


INFLAMMATION    OF    THE   EDGE    OF    THE    LIDS.       BLEPHARITIS. 

Many  individuals,  especially  those  with  a  scrofulous  dispo- 
sition and  tender  skin,  are  affected  with  a  slight  redness  and 
exfoliation  along;  the  outer  angle  of  the  lids. 

The  skin  on  those  parts  is  generally  in  an  irritated  condition, 
which  upon  the  slightest  cause  assumes  an  inflammatory  character, 
often  connected  with  conjunctivitis.  Protection  from  injurious 
influences,  and,  where  there  is  great  irritability,  the  use  of  mild 
astringents,  for  instance,  lead-water,  is  the  proper  treatment. 

Severe  inflammation  of  the  edge  of  the  lids  may  occur  as  a 
consequence  of  other  diseases  which  have  caused  long-continued 
hypersemia  of  the  conjunctiva  and  abnormal  retention  of  the 
lachrymal  secretions,  such,  for  instance,  as  chronic  inflammation 
of  the  conjunctiva  or  cornea,  or  stricture  of  the  nasal  duct. 
Blepharitis,  however,  occurs  just  as  often  as  an  idiopathic  disease, 
and  gives  rise  during  its  course  to  secondary  diseases  of  other 
parts  of  the  eye. 

The  mildest  form  of  blepharitis  is  that  in  which  the  inflamma- 
tion occurs  at  circumscribed  points  along  the  edge  of  the  lids 
while  the  intervening  spaces  remain  normal. 

At  one  or  more  places  on  the  edge  of  the  lids  occur  circum- 
scribed redness  and  swelling.  The  cilia  are  glued  together  by 
scabs,  whose  removal  leaves  raw  bleeding  places,  or  deep,  crater- 
like ulcers  between  the  cilia.  If  the  eyes,  as  when  sleeping,  are 
kept  for  a  long  time  closed,  the  edges  of  the  lids  become  glued 
together  by  the  dried  secretions. 

These  ulcers  are  best  cured  by  carefully  removing  the  scabs  and 
causing  an  eschar  upon  the  raw  surfaces  by  the  application  of 
some  metallic  caustic.  Pencillings  with  acetate  of  lead  or  nitrate 
of  silver  in  2  or  3  per  cent,  solution,  or  with  a  concentrated  solu- 
tion of  sulphate  of  copper,  or  finally  with  the  red  oxide  of  mercury, 
218 


BLEPHARITIS.  219 

are  the  best  applications.  In  many  cases,  especially  where  con- 
siderable thickness  is  associated  with  moderate  excoriation  of  the 
edges  of  the  lids,  I  have  seen  very  good  results  from  the  pencil- 
ling with  tincture  of  iodine  along  the  line  of  the  cilia. 

If  the  local  treatment  must  be  intrusted  to  the  patient  himself, 
prescribe  a  wash  of  acetate  of  lead,  10  drops  liq.  plumb,  acet.  to 
a  teacup  of  water,  and  a  salve  of  nitrate  of  silver,  1  to  2  per  cent., 
or  the  red  oxide  or  ammonio-chloride  of  mercury,  1  to  2  per  cent., 
generally  in  combination  with  the  oxide  of  zinc  and  the  addition 
of  a  solution  of  lead,  for  instance : 

R  White  precipitate  of  mercury,  0.2-0.3  =  about  gr.  iii-ivss  ; 
Oxide  of  zinc,  0.3-0.5^     "        "    ivss-vii.ss; 

Glycerine  ointment,  10.0         =     "        5    iiss ; 

Sol.  acetate  of  lead,  gtt.  4-6. 

These  applications  are  none  of  them  of  any  use  until  the  dried 
secretions  about  the  cilia  have  been  removed  and  the  ulcers  ex- 
posed. The  crusts  generally  cling  very  tenaciously,  so  that  their 
removal  is  painful,  and  is  gladly  neglected  by  the  patients.  Tlie 
process  is  made  easier  by  previously  softening  them  with  oil  or 
warm  cataplasms.  When  the  crusts  are  removed,  the  salve  must 
be  well  rubbed  upon  the  ulcers  so  as  to  cause  a  burning  sensation. 

Another  form  of  blepharitis  is  that  in  which  the  inflammation, 
ulceration,  suppuration,  formation  of  crusts,  and  thickening  of  the 
edges  extend  along  the  whole  length  of  the  lids.  After  long  con- 
tinuance of  the  disease  the  cilia  become  straggling  and  irregular. 
They  are  either  entirely  destroyed  by  the  deep  ulcers  at  their  bases 
or  they  are  replaced  by  ill-developed  after-growths. 

The  most  dangerous  and  obstinate  form  of  blepharitis  is  that 
in  which  there  is  at  the  same  time  a  wide-spread  disease  of  the  in- 
tegument of  the  lids.  Besides  the  excoriations  on  the  edges  of  the 
lids,  others  occur,  first  near,  then  farther  from  the  edges ;  they  are 
covered  with  flat  crusts,  which  upon  removal  expose  raw,  bleeding 
surfaces.  The  skin  loses  its  softness  and  elasticity,  and  becomes 
shrunken.  The  first  consequence  of  this  is  an  ectropion,  which 
generally  very  early  turns  the  puncta  lacrymalia  outward  and 
interferes  with  their  function.  Later,  the  edge  of  the  lid  be- 
comes more  and  more  rounded  off;  the  inner  angle,  as  well  as 
the  intermarginal  part,  gradually  disappears;  no  trace  can  be  seen 
of  the  openings  of  the  Meibomian  tarsal  glands,  or  the  puncta 


220  BLEPHARITIS. 

lacrymjilia;  the  position  of  the  outer  angle  of  the  lid  can  be  recog- 
nized only  with  difficulty  by  the  few  remaining  cilia,  or  rather 
by  the  poorly  developed,  pale  hairs  which  have  taken  the  place  of 
them. 

These  changes  stand  in  such  close  causal  relations  that  the  dis- 
ease runs  in  a  vicious  circle.  The  lachrymal  secretion  is  increased 
by  the  inflammatory  irritation;  the  absence  of  the  normal  lubri- 
cation of  the  lids  by  the  secretion  of  the  Meibomian  tarsal  glands, 
and  the  impossibility  of  conducting  away  the  tears  through  the 
canaliculi,  cause  them  to  drip  contiuually  over  the  edge  of  the 
lid.  The  irritation  and  shrinking  of  the  skin  and  the  already 
existing  ectropion  are  thereby  increased;  the  everted  conjunctiva 
causes  the  lids  to  appear  as  if  bordered  by  a  red  seam;  they  close 
only  imperfectly  upon  the  eyeball;  and  finally,  the  combined  effect 
of  the  shortening  of  the  skin  of  the  lids  and  of  the  ectropion  is 
that  the  palpebral  fissure  can  no  longer  be  sufficiently  closed. 
The  eye  is  deprived  of  the  greater  part  of  its  natural  protection, 
and,  as  a  consequence,  corneal  ulcers  are  very  apt  to  appear, 
especially  on  its  lower  margin. 

The  disease  does  not  always  proceed  so  far  as  this,  but  at  an 
even  earlier  stage  it  has  passed  the  possibility  of  recovery.  If 
ectropion  exist,  if  the  angle  of  the  lids  be  rounded  down,  and  if  the 
openings  of  the  tarsal  glands  and  the  puncta  lacrymalia  be  oblit- 
erated, a  restitutio  ad  integrum  is  not  possible.  Proper  treatment 
in  the  early  stages  is  therefore  not  to  be  neglected.  Especially 
is  the  tear-passage  to  be  kept  open,  since  a  perpetual  dripping  of 
the  tears  has  a  most  hurtful  influence.  Whenever  the  punctum 
lacrymale  is  drawn  outward  from  its  normal  position,  the  canalic- 
ulus is  to  be  split  and  kept  open.  It  is  well  also  to  ascertain  the 
permeability  of  the  nasal  duct.  If  ectropion  develop,  its  effect 
should  be  resisted  by  proper  operative  treatment.  Snellen's  ectro- 
pion stitch,  to  be  described  later,  is  often  a  very  suitable  method. 
Among  the  above-named  external  applications,  the  white  precipi- 
tate of  mercury,  alone  or  in  combination  with  the  oxide  of  zinc, 
is  especially  recommended.  Quite  celebrated  is  its  combination 
with  tar: 

R  White  precipitate  of  mercury,  0.5-0.75  ^=  about  gr.  72-llf  ; 
Liquid  tar,  2.0  =      "      3     ii 

Simple  ointment,  7.5  =      "32. 


I 


PEDICULI.       HORDEOLUM.  221 

Somewhat  rarely,  lice  are  found  upon  the  cilia  and  eyebrows. 
They  cause  chronic  inflammation  and  great  itching.  They  are 
so  small  as  to  be  easily  overlooked,  if  not  examined  with  a  lens. 
The  nits  fastened  on  the  cilia  cause  them  to  appear  as  if  sprinkled 
with  a  black  powder.*  The  evil  is  removed  by  cleanliness  and 
the  use  of  mercurial  ointment,  or  pencilling  with  a  |  per  cent. 
solution  of  corrosive  sublimate,  being  careful  to  allow  none  to  get 
into  the  eye. 

There  often  develop  on  the  skin  of  the  lids,  either  with  or  with- 
out other  simultaneous  conjunctival  aifections,  hyaline  cysts,  Avhich 
are  very  small,  at  most  not  larger  than  a  poppy-seed,  and  which 
cause  sensitiveness  of  the  eye.  It  is  sufficient,  simply  to  break 
them  with  the  finger-nail,  or  some  other  instrument. 

The  hordeolum  or  stye  occurs  in  the  form  of  a  small,  inflamed, 
tender  swelling  on  the  edge  of  the  lid.  It  increases  in  size  for 
several  days,  when  resolution  or,  more  frequently,  suppuration 
occurs.  In  the  latter  case  the  tumor  points  and  breaks  at  the 
outer  edge  of  the  lid.  Since  the  place  of  the  rupture  is  always 
near  the  cilia,  the  hordeolum  is  generally  regarded  as  an  inflam- 
mation of  the  hair  follicles. 

In  many  cases  the  hordeolum  is  associated  with  great  swelling 
of  the  lids,  and,  when  near  the  outer  canthus,  with  swelling  and 
reddening  of  both  lids.  The  swelling  of  the  lids  may  be  so  great 
that,  at  first  glance,  the  existence  of  blennorrhoeal  conjunctivitis 
may  suggest  itself.  Such  a  diagnostic  error  may,  however,  be 
easily  avoided.  Aside  from  the  fact  that  the  signs  of  blennor- 
rhoea  are  absent  from  the  conjunctiva,  the  swelling  of  the  lids  is 
always  localized,  being  greatest  near  the  hordeolum.  Moreover, 
the  circumscribed  inflammatory  tumor  may  be  easily  recognized 
by  the  touch. 

Frequently  several  hordeola  follow  rapidly  one  after  the  other, 
or  they  develop  with  pauses  of  some  weeks  between,  just  as  is  the 
case  with  furuncles. 

The  treatment  may  be  limited  to  the  use  of  warm  fomentations. 
The  spontaneous  rupture  occurs  generally  without  any  difficulty, 
but  if  it  be  unduly  delayed  the  process  may  be  hastened  by  punc- 
ture.    Where  there  is  a  persistent  tendency  to  the  develo})ment  of 

*  Mackenzie,  Practical  Treatise,  London,  1854,  pag.  228. 


222  CHALAZION.  . 

hordeola,  especially  in  scrofulous  individuals,  the  ordinary  saline 
remedies,  salt-baths,  etc.,  are  recommended. 

Anomalies  of  the  Meibomian  tarsal  glands  are  generally  due  to 
retention  of  their  secretion.  It  collects  often  in  the  excretory 
ducts,  and  forms  small  round  prominences  upon  the  tarsal  part  of 
the  conjunctiva,  near  the  edge  of  the  lid;  they  cause  to  the  patient 
a  sensation  of  pressure.  For  their  relief  it  is  sufficient  to  split 
the  little  tumors  in  the  direction  of  the  excretory  ducts:  the  con- 
tents, a  mass  resembling  stearine,  are  then  easily  pressed  out. 

Oftener,  especially  in  old  people,  the  retention  occurs  in  the 
deeper  parts  of  the  glands.  At  their  posterior  ends  they  become 
distended  by  hardened  secretions,  forming  small  yellow  tumors 
above  the  surface  of  the  conjunctiva.  In  some  cases  deposits  of 
lime,  forming  stony  concretions,  are  found  in  the  retained  gland- 
ular secretions  (lithiasis  conjunctivae).  If  this  condition  cause 
local  irritation  of  the  conjunctiva,  chronic  conjunctivitis,  or  other 
annoyances,  the  glands  may  be  opened  with  a  cataract-needle  and 
the  contents  evacuated. 

Chalazion  is  the  name  given  to  a  circumscribed  tumor  in  the 
tarsal  cartilage.  There  develops  generally  without  any  annoy- 
ances a  swelling  in  the  cartilage  of  the  lids.  In  some  cases  it 
remains  for  a  long  time  small  and  stationary,  in  others  it  grows 
gradually  and  forms  a  tumor,  projecting  on  the  outer  surface  of  the 
lid.  Since  it  develops  in  the  tarsus  itself,  the  tumor  can  be  moved 
only  with  the  cartilage,  and  not  upon  it.  If  the  eyelid  be  everted, 
the  corresponding  part  of  the  tarsus  appears  slightly  yellow,  and 
often  somewhat  elevated. 

The  contents  of  a  chalazion  are  at  first  a  soft,  light-gray  mass, 
consisting  of  round  or  oval,  slightly  granular  cells  of  various  sizes. 
Fine  blood-vessels  ramify  within  the  tumor.  Large  chalazia, 
which  have  existed  a  long  time,  often  have  light-yellow  fluid 
contents. 

The  swelling  may  vary  in  size  from  that  of  a  pea  to  that  of  a 
hazel-nut.  Its  spontaneous  rupture  occurs  but  seldom,  but  when 
it  does,  is  always  on  the  conjunctival  surface  of  the  tarsus.  Granu- 
lations may  grow  out  from  the  interior  of  the  tumor,  and,  becoming 
flattened  by  pressure  against  the  eyeball,  spread  out  on  all  sides 
about  the  place  of  rupture. 

In  the  beginning,  and  while  the  chalazia  are  still  small,  their 


CHALAZION.  223 

resolution  may  often  be  brought  about  by  external  applications. 
Iodide  of  potassium,  in  the  form  either  of  an  ointment  or  of 
a  strong  solution  in  glycerine,  is  the  best  to  employ  for  this 
purpose. 

If  the  attempt  to  cause  resolution  does  not  succeed,  it  is  ad- 
visable to  leave  very  small  hard  chalazia  to  themselves  ;  but  when 
the  tumors  attain  such  a  size  that  they  become  noticeable  and 
may  be  regarded  as  a  deformity,  they  should  be  removed  by 
operation.  The  lid  is  to  be  everted,  and  the  tumor  split  upon 
the  conjunctival  surface  in  a  direction  perpendicular  to  the  edge 
of  the  lid.  The  contents  are  then  evacuated,  partly  by  press- 
ure on  the  outer  surface  of  the  lid,  partly  by  a  Daviel  spoon,  or 
some  such  suitable  instrument  introduced  into  the  cavity  of  the 
tumor. 

Subsequently  the  cavity  may  be  cauterized  with  nitrate  of  sil- 
ver, to  be  followed  by  caVeful  neutralization  by  a  solution  of  salt. 
Still,  in  most  cases  this  cauterization  appears  unnecessary.  The 
external  prominence  is  not  immediately  removed  by  the  incision, 
since  the  tough  tissue  of  the  tarsus  only  gradually  resumes  its 
normal  shape.  The  final  reslilt  of  this  method  is  a  return  to  the 
normal  relations,  and  I  have  never  found  it  necessary  to  remove 
a  chalazion  from  the  outer  surface  of  the  lid. 

If  after  spontaneous  rupture  of  the  chalazion  granulations  have 
formed  in  the  cavity  of  the  tumor,  they  are  to  be  clipped  off  with 
the  shears  and  the  wall  of  the  cavity  cauterized  with  nitrate  of 
silver. 

Occasionally  there  occur  circumscribed  acute  inflammations  in 
the  tarsal  cartilages,  which,  proceeding  probably  from  the  Meibo- 
mian glands,  cause  the  same  symptoms  as  a  hordeolum.  The  dif- 
ference between  the  two  is,  that  these  tumors  are  farther  from  the 
edge  of  the  lid  than  the  hordeolum,  and  that  when  suppuration 
occurs  they  break  not  at  the  outer  edge  of  the  lid,  but  always  on 
the  inner  surface.  The  treatment  at  the  beginning  is  by  warm 
poultices :  still,  it  is  not  advisable  to  wait  for  their  spontaneous 
rupture,  which  is  generally  delayed  by  the  resistance  of  the  tarsus. 
So  soon  as  the  tumor  is  perceptible  above  the  general  conjunctival 
surface  of  the  lid  and  begins  to  grow  yellow,  it  should  be  split 
through  the  conjunctiva  in  a  direction  perpendicular  to  the  edge 
of  the  lid. 


224       HERPES  ZOSTER   FRONTALIS   STVE   OPHTHALMICUS. 


HERPES   ZOSTER    FRONTALIS   SIVE   OPHTHALMICUS. 

Herpes  zoster  in  the  region  of  the  ramifications  of  the  first 
branch  of  the  fifth  nerve  is  a  rather  rare  affection.  The  herpetic 
eruption  is  most  frequent  in  the  region  of  the  nervus  frontalis ; 
it  may,  however,  correspond  with  the  distribution  of  the  nervus 
naso-ciliaris  upon  the  nose,  even  to  its  extremity.  Exceptionally, 
the  eruption  occurs  in  the  region  of  the  second  branch  of  the  fifth 
nerve.  Hutchinson*  states  that  the  participation  of  the  eye  in 
the  process  is  most  frequent  when  the  presence  of  vesicles  along 
the  side  of  the  nose  shows  that  the  naso-ciliary  branch  is  affected, 
explaining  this  tendency  by  the  fact  that  the  long  root  of  the 
ciliary  ganglion  and  the  long  ciliary  nerves  spring  from  the  naso- 
ciliary branch  of  the  fifth  pair.  Bowman, f  however,  could  not 
satisfy  himself  of  this  coincidence,  and  Horner|  describes  a  ease 
of  zoster  with  iritis,  in  which  the  eruption  upon  the  side  of  the 
nose  entirely  failed. 

The  affection  begins  generally  with  severe  neuralgia  of  the  fifth 
nerve.  After  some  days  there  appear  swelling  and  redness  of 
the  skin  and  an  eruption  of  groups  of  herpetic  vesicles,  which 
gradually  dry  and  become  converted  into  hard  crusts,  which  gen- 
erally leave  deep,  permanent  scars  when  they  fall  off.  Almost 
always  the  part  of  the  skin  affected  remains  a  long  time  anaes- 
thetic, but  it  may  be  the  seat  of  severe  neuralgia.  This  subse- 
quent neuralgia  appears  to  be  particularly  obstinate  in  old  people, 
and  it  may  be  so  severe  as  seriously  to  reduce  their  strength. 
Joy  Jeffries  relates  a  case  in  which  a  patient  80  years  of  age  died 
in  this  way  in  consequence  of  herpes  ophthalmicus.  Horner 
observed,  too,  a  remarkable  elevation  of  temperature  upon  the 
affected  half  of  the  forehead,  which  continued  for  a  month  and  a 
half  after  its  first  appearance.§ 

The  affection  of  the  eyes  may  precede  the  eruption  on  the  skin, 
but  generally  follows  some  days  after  it.  According  to  Horner, 
the  corneal  affection  always  begins  with  the  appearance  of  a  series 


*  Ophthalmic  Hospital  Reports,  1866,  vol.  v.  3,  pag.  214. 

t  Ibid.,  1867,  vol.  vi.  1,  pag.  3. 

X  Klin.  Monatsbl.  f.  Augenheilk.,  1868,  pag.  371. 

§  Ibid.,  1871,  pag.  321. 


HERPES   ZOSTER    FRONTALIS   SIVE   OPHTHALMICUS.        225 

of  transparent  vesicles,  grouped  oftener  upon  the  margin  than  at 
the  centre  of  the  cornea.  These  vesicles  burst,  leaving  an  irreg- 
ular loss  of  substance,  while  the  cornea  becomes  cloudy  over  a 
considerable  extent  of  its  surface.  Simultaneously  an  anaesthesia 
over  nearly  the  whole  surface  of  the  cornea  is  observable.  Very 
interesting,  too,  is  the  simultaneous  occurrence  of  marked  diminu- 
tion of  the  intraocular  pressure,  which,  in  the  cases  observed  by 
Horner,  disappeared  only  slowly  and  simultaneously  with  the 
recovery  of  the  cornea  and  the  return  of  a  normal  temperature 
on  the  side  affected.  Recovery  from  the  corneal  affection  is  gen- 
erally slow,  leaving  opacities  behind  it.  An  iritis  is  often  asso- 
ciated with  the  keratitis ;  still,  it  may  occur  independent  of  the 
corneal  affection. 

In  severe  cases  irritability  of  the  eyes  may  remain  for 
months. 

Paralysis  of  the  oculo-motorius  has  been  observed  by  Hutchin- 
son* as  a  rare  complication  of  herpes  frontalis.  I  also  have  ob- 
served one  case  in  which  mydriasis  and  paresis  of  accommodation 
remained  in  the  affected  eye. 

In  reference  to  diagnosis,  it  is  likely  to  be  confounded  with  ery- 
sipelas. The  pains  which  precede  the  eruption,  and  the  limitation 
of  the  disease  to  one-half  of  the  face,  are  at  the  beginning  the 
essential  points  to  be  observed  in  the  diagnosis.  Herpes  frontalis 
never  extends  beyond  the  median  line,  while  erysipelas  observes 
no  such  law.  The  swelling  of  the  skin  is  less  than  in  erysipelas, 
and  in  many  cases  is  quite  slight;  the  herpetic  vesicles  are  smaller, 
more  sharply  circumscribed,  and  more  numerous  than  are  those  in 
erysipelas.  In  the  further  course  of  the  disease  the  anaesthesia  of 
the  parts  affected  and  the  formation  of  scars  are  characteristic  of 
herpes. 

The  treatment  of  the  affection  of  the  eyes  consists  in  rest  and  in 
the  use  of  atropine.  On  account  of  the  severe  subsequent  neu- 
ralgia. Bowman  has  performed  subcutaneous  neurotomy  in  several 
cases,  partly  with  temporary  and  partly  with  permanent  good 
results. 

According  to  Horner,  an  eruption  of  transparent  vesicles 
grouped  upon  the  cornea  occurs  in  connection  with  herpes  labialis 

*  Ophthalmic  Hospital  Keports,  vol.  vi.  3,  pag.  183. 


226  ECZExMA    AND    EEYSIFELAS   OF   THE    LIDS. 

following  pneumonia  or  severe  catarrhal  aifections  of  the  respira- 
tory organs. 

Eczema  of  the  palpebral  skin  occurs  quite  frequently  in  chil- 
dren in  connection  with  eczema  of  the  face.  The  hypersemia 
generally  extends  from  the  skin  through  the  entire  thickness  of 
the  lid  to  the  conjunctiva,  there  causing  catarrhal,  blennorrhceal, 
or  even  diphtheritic  inflammation,  by  which  the  swelling  of  the 
lids  is  still  further  increased.  Keratitis  phlyctsenulosa,  and  its 
consequences,  ulceration  or  pannus  of  the  cornea,  are  frequent 
complications. 

Long-continued  eczema  of  the  lids,  especially  with  co-existing 
conjunctival  swelling  and  blepharitis,  favors  the  occurrence  of 
ectropion  by  the  shrinking  of  the  skin. 

Erysipelas  of  the  eyelids  in  cases  of  facial  erysipelas  is  not  in- 
frequently seen.  If  the  inflammation  be  principally  upon  the 
eyelids,  one  must  be  careful  in  the  diagnosis  to  distinguish  it  from 
conjunctival  blennorrhcea  and  from  acute  dacryocystitis. 

The  inflammation  often  extends  from  the  eyelids  into  the  orb- 
ital connective  tissue,  and  by  involving  the  optic  nerve  may  cause 
blindness.  Severe  inflammations  may  go  on  to  suppuration  of 
the  subcutaneous  connective  tissue  of  the  lids  and  wide-spread 
destruction  of  their  skin.  If  there  be  reason  to  fear  such  results, 
incisions  should  be  made  in  the  direction  of  the  fibres  of  the 
orbicularis. 

After  erysipelas  there  often  remains  a  pale,  painless,  cedematous 
swelling  of  the  lids,  sometimes  so  great  that  they  can  scarcely  be 
opened.  In  such  cases  the  use  of  iodide  of  potassium,  either  as  a 
salve  or  in  a  strong  solution  in  glycerine  applied  with  a  pencil,  or 
pure  tincture  of  iodine,  is  indicated. 

It  is  only  seldom  in  the  course  of  erysipelas  that  extensive 
gangrene  occurs  upon  the  lids  or  within  the  orbit. 

Exceptionally,  erysipelas  of  the  lids  occurs,  of  an  exceedingly 
severe  and  gangrenous  character  from  the  very  first.  Cases  of 
this  sort  may  prove  quickly  fatal,  and  are  generally  regarded  as 
the  consequence  of  an  infection  with  animal  poison.  Malignant 
pustule  upon  the  eyelid  has  been  observed. 

Abscesses  of  the  eyelids  occur  ofteuer  in  children  than  in  adults. 
They  are  generally  in  the  upper  lid,  and  cause  there  a  noticeable 
swelling.     The  treatment  is  by  warm  poultices  and  opening  of 


ULCERS   AND   TUMORS   OF   THE    LIDS.  227 

the  abscesses  so  soon  as  fluctuation  is  felt  or  pus  can  be  seen 
through  the  skin. 

Sv^philitic  ulcers  occur  on  the  skin  of  the  eyelids,  and  may  be 
either  primary  or  secondary.  They  generally  show  a  great  tend- 
ency to  extend  upon  the  surface,  and  often  penetrate  also  to  a 
considerable  depth.  If  they  be  situated  near  the  edge  of  the  lid 
they  are  very  apt  to  involve  the  conjunctiva.  This  appears  to 
occur  oftenest  near  the  inner  canthus.  But  syphilitic  ulcers  occur 
on  other  parts  of  the  conjunctiva,  such  as  the  tarsus  and  fornix, 
and  persist  with  great  obstinacy. 

The  treatment  demands  local  cauterization  with  nitrate  of  silver 
or  the  application  of  the  red  oxide  of  mercury  to  the  outer  surface 
of  the  lid,  and  in  addition  to  this  suitable  constitutional  treatment. 

Lupus  of  the  lids  generally  extends  from  the  face;  it  may,  how- 
ever, appear  primarily  on  the  lids.  When  it  involves  the  con- 
junctiva it  causes  it  to  shrink.  Symblepharon,  corneal  opacities, 
and  absolute  blindness  follow. 

Circumscribed  isolated  lupus  ulcers  also  occur  upon  the  ocular 
conjunctiva. 

Epithelioma  often  develops  upon  the  edges  of  the  lids,  and  in 
time  destroys  them.  Its  earliest  possible  extirpation,  combined 
when  practicable  with  a  blepharoplastic  operation  by  which  to 
replace  the  lost  tissue,  is  the  proper  treatment. 

Telangiectasia  of  the  lids  is  not  uncommon,  and  may  be  situated 
either  in  the  skin  alone  or  in  the  subcutaneous  connective  tissue, 
or  in  both  at  the  same  time.  These  tumors  often  extend  deep 
into  the  orbit. 

The  treatment  is  not  essentially  different  from  that  of  telangi- 
ectasia in  other  parts  of  the  body.  Superficial  cauterization  with 
fuming  nitric  acid,  inoculation  with  vaccine  virus,  or  puncture 
with  the  hot  iron,  or,  still  better,  the  galvano-caustic  puncture, 
is  suitable  treatment  for  most  cases.  The  attempt  must  always 
be  made  to  cause  as  little  loss  of  skin  as  possible. 

Congenital  cysts  of  the  eyelids  are  generally  situated  on  the 
temporal  side  near  the  eyebrow.  They  contain  a  serous,  often 
atheromatous,  fluid,  and  often,  too,  hairs,  which  grow  from  the 
inner  walls  of  the  cyst.  They  often  lie  beneath  the  orbicularis, 
may  penetrate  to  a  considerable  depth,  and  may  be  connected  with 
the  periosteum. 


228  SEBOREHCEA,  ETC. 

Their  extirpation  demands  a  free  incision  of  the  skin  and  a 
careful  dissection  of  the  external  wall  to  its  posterior  part.  If 
during  the  operation  the  cjst  be  wounded,  it  must  nevertheless  be 
carefully  extirpated,  since  if  any  part  be  left  behind  it  is  apt  to 
delay  the  healing  of  the  wound  or  cause  it  to  break  open  anew. 

Abnormal  secretion  of  the  skin  of  the  eyelids  occurs  as  a  local 
hypersecretion  of  the  sweat  glands  (ephidrosis).  It  causes  a  sen- 
sation of  itching  and  biting  upon  the  lids,  a  high  degree  of  irrita- 
tion of  the  conjunctiva  and  of  the  edges  of  the  lids,  and  excoriation 
of  the  skin. 

Seborrhoea  is  an  abnormal  secretion  from  the  sebaceous  glands 
of  the  lids. 

Chromhidrosis  is  the  name  given  to  an  abnormal,  generally 
dark-blue  or  black  discoloration  of  certain  portions  of  the  eyelids. 
It  appears  suddenly,  and  may  easily  be  washed  off  with  water  or 
glycerine,  but  appears  again  in  a  Avholly  irregular  manner.  Re- 
specting the  nature  of  this  affection  nothing  is  absolutely  known, 
but  it  is  certain  that  such  cases  are  not  all  simulated. 

Xanthelasma  or  vitiligoidea  are  names  given  to  a  peculiar  dis- 
ease of  the  skin  which,  from  anatomical  investigations,*  appears 
to  be  due  to  the  fact  that  the  connective-tissue  cells  in  the  parts 
affected  are  filled  with  yellow  fat.  It  appears  as  dark,  straw- 
colored  spots  slightly  elevated  above  the  general  surface  of  the 
skin,  which  develop  very  slowly  and  are  almost  always  situated 
on  the  eyelids.  Similar  spots  have  in  rare  cases  been  observed 
upon  the  ears,  the  elbows,  and  the  hands. 

BLEPHAROSPASM. 

Spasm  of  the  orbicularis  occurs  in  very  different  forms.  The 
mildest  consists  in  short  twitchings  of  some  few  fibres  of  the 
orbicularis,  generally  in  the  lower  lid,  near  the  outer  canthus, 
which  last  only  a  few  minutes,  are  due  to  no  known  cause,  and 
disappear  again,  causing  only  a  temporary  uncomfortable  sensation. 

Generally  only  those  cases  are  called  blepharospasm  in  which 
the  palpebral  fissure  is  absolutely  closed.     There  may  be  but  a 


*  Von  Baerensprung,  Deutsche  Klinik,  1855,  pag.  17  ;  Waldeyer,  Virchow's 
Arch.,  1871,  pag.  318;  Virchow,  Arch.  f.  Path.  Anat.,  1871,  pag.  504;  Manz, 
Klin.  Monatsbl.  f.  Augenheilk.,  1871,  pag.  251. 


BLEPHAROSPASM.  229 

single  spasm  or  they  may  be  repeated.  The  eyelids  are  suddenly 
closed  during  some  seconds  or  minutes  by  spasmodic  twitchings 
and  then  opened  again.  The  spasms  occur  without  any  apparent 
cause  or  warning,  in  diiFerent  cases  with  different  degrees  of 
severity  and  frequency,  often  wnth  such  short  intervals  as  to  make 
it  dangerous  for  the  patients  to  walk  upon  frequented  streets.  The 
usual  complications  are  hyj)er8emia  of  the  connective  tissue,  dila- 
tation of  the  veins  of  the  lids,  and  more  or  less  photophobia. 

Besides  the  cases  of  spasmodic  tAvitching  of  the  orbicularis, 
there  is  another  class  of  cases  in  which  there  is  a  tonic  spasmodic 
closure  of  the  eye.  For  this  very  reason  the  patients  are  exceed- 
ingly sensitive  to  light,  generally  carry  the  head  bent  forward, 
and  are  not  able,  with  the  greatest  effort,  to  open  their  eyes. 
They  resist  also,  with  all  their  power,  the  forcible  opening  of  the 
lids,  on  account  of  the  painful  dazzling  sensation  thereby  caused, 
while  the  eye  itself  rolls  s])asmodically  upward  and  is  hidden  under 
the  upper  lid. 

Scrofulous  blepharospasm  is  the  most  frequent  of  these  forms. 
Keratitis,  in  scrofulous  individuals,  is  generally  connected  with  a 
much  more  irritable  condition  than  in  those  otherwise  healthy. 
So  long,  however,  as  an  acute  inflammatory  process  is  evident 
in  the  cornea,  the  closure  of  the  lids,  the  contraction  of  the  pupil, 
and  the  increased  flow  of  tears  will  be  regarded  as  reflex  symp- 
toms. But  if  the  inflammatory  process  be  ended,  and  if  the  lids 
are  still  spasmodically  closed,  the  blepharospasm  loses  the  character 
of  a  simple  reflex  affection. 

The  constitutional  nature  both  of  the  keratitis  and  of  the 
scrofulous  blepharospasni  is  shown  by  the  fact  that,  in  the  great 
majority  of  cases,  they  occur  bilaterally.  It  is  advisable  to  resort 
to  the  chloroform  narcosis  in  order  to  make  a  more  thorough 
examination  of  the  cornea.  The  lids  can  be  then  easily  separated, 
and  it  is  only  in  this  way  that  the  eye  can  be  seen  in  its  natural 
condition,  while  if,  without  the  anaesthetic,  the  lids  be  forcibly 
opened,  the  pain  and  dazzling  cause  such  injection  of  the  con- 
junctiva, and  under  certain  circumstances  of  the  cornea  also,  such 
a  flow  of  tears,  etc.,  that  it  is  imi^ossible  to  decide  whether  inflam- 
mation exist  or  not.  As  regards  treatment,  this  question  is  very 
important.  If  in  scrofulous  blepharospasm  there  be  no  inflam- 
mation of  the  cornea,  the  ordinary  local  applications  employed  in 


230  BLEPHAROSPASM. 

keratitis  (atropine,  ointment  of  suboxide  of  mercury,  calomel, 
etc.)  are  not  indicated,  on  the  contrary,  are  hurtful. 

Often  the  corneal  affection  is  healed,  or  nearly  so,  but  there 
is  an  inflammatory  swelling  and  secretion  of  the  conjunctiva,  by 
which  the  irritability  is  maintained.  In  such  cases  the  blepharo- 
sjjasm  often  disappears  under  local  treatment  of  the  conjunctiva, 
best  done  Avith  a  1  or  2  per  cent,  solution  of  nitrate  of  silver. 

A  proper  constitutional  treatment  is,  however,  generally  of  the 
greatest  importance.  Salt-baths  are  excellent,  and  when,  as  is 
frequently  the  case,  the  eyelids  or  the  entire  face  appear  abnor- 
mally warm,  washing  or  dipping  the  face  in  ice-water  gives  relief. 

Just  as  reflex  symptoms  which  have  been  excited  by  keratitis 
may  continue  after  the  inflammation  has  run  its  course,  so,  too, 
can  blepharospasm  be  caused  by  foreign  bodies  which  wound  the 
surface  of  the  cornea.  In  such  cases  a  spasmodic  closure  of  the 
lids  often  continues  long  after  the  foreign  body  has  been  removed. 
In  the  course  of  time  tlie  spasm  may  pass  over  from  the  eye  first 
injured  to  the  other  one. 

All  these  cases  are  due  to  a  ])rimary  irritation  of  the  sensitive 
nerves  of  the  cornea  or  conjunctiva,  but  the  reflex  spasm  lasts 
much  longer  than  the  primary  irritation. 

Irritation  of  other  branches  of  the  fifth  nerve,  especially  in 
the  region  of  the  supra-orbitalis  and  dental  nerves,  is  mentioned 
as  a  cause  of  blepharospasm.  Compression  of  the  trunk  of  the 
nerve  affected,  especially  where  it  lies  against  a  bone,  interrupts 
the  reflex  current,  and  for  the  moment  relieves  the  spasm. 

A  very  peculiar  form  of  blepharospasm  has  been  j)ointed  out 
by  Donders*  as  "  sympathetic  neurosis."  After  one  eye  had  been 
lost  by  irido-cyclitis,  following  an  injury,  blepharospasm  appeared 
in  the  other,  otherwise  healthy  eye.  It  was  persistent,  closed  the 
lids  absolutely,  and  disappeared  immediately  after  the  extirpation 
of  the  primarily  diseased  eye.  There  was  in  that  case  evidently 
a  reflex  spasm,  whose  source  was  in  the  eye  first  injured. 

Blepharospasm  may  appear  in  connection  with  spasms  over  the 
entire  region  of  the  facialis,  or,  after  having  continued  a  long 
time,  it  may  cause  such  spasms.  Other  nervous  tracts  may  be- 
come gradually  involved. 

*  Klin.  Monatsbl.,  1863,  pag.  448. 


PTOSIS.  231 

Mackenzie*  mentions  unilateral  blepharospasm  after  injuries  of 
the  head,  and  warns  against  confounding  it  with  paralysis  of  the 
levator  palpebrae  superioris.  The  twitching  at  the  angle  of  the 
lids,  and  the  resistance  when  the  attempt  is  made  to  lift  the  lids 
with  the  fingers,  confirm  the  diagnosis. 

Finally,  hysteria  should  be  named  as  a  cause  of  blepharospasm. 

The  treatment  of  blepharospasm  is  generally  not  very  satisfac- 
tory. The  usual  means  employed  are  the  cold  douche,  cold  face- 
baths,  and  counter-irritation  on  the  forehead,  the  temporal  region, 
or  the  mastoid  process.  Treatment  is  most  successful  in  those 
cases  of  reflex  spasm  in  which  it  is  possible  to  discover  the  place 
of  the  primary  irritation.  In  such  cases  Von  Graefef  recom- 
mended subcutaneous  injections  of  morphine.  He  also  practised 
the  division  of  the  nervous  trunk  which  conducts  the  reflex  cur- 
rent, as  first  proposed  by  Romberg.  Good  residts  may  be  ex- 
pected from  this  operation  in  those  cases  in  which  the  spasm  can 
be  interrupted  by  pressure  on  the  trunk  of  the  nerve.  The 
supra-orbital  nerve  presents  oftenest  the  indications  for  this  oper- 
ation. 

It  is,  however,  in  this  connection  to  be  remembered  that  in 
many  cases  the  spasm  may  be  interrupted  by  pressure  upon  quite 
distant  points,  as,  for  instance,  in  a  case  observed  by  Charles  Bell, 
by  pressure  upon  the  cartilages  of  the  ribs  in  the  left  hyjjochon- 
driac  region. |  In  hysterical  patients,  also,  one  often  sees  the 
spasm  temporarily  interrupted  by  pressure  on  any  indifferent  part 
of  the  body. 

PTOSIS. 

The  inability  to  raise  the  upper  lid  may  be  due  to  imperfect 
action  of  the  levator  palpebrse  muscle,  for  instance,  after  injuries. 
It  may  be  due  to  paralysis  of  the  oculo-motorius,  or  it  may  be 
that,  in  consequence  of  pathological  changes,  the  lid  has  become 
too  heavy,  as  may  be  the  case  in  chronic  conjunctival  inflamma- 
tions, such  as  trachoma,  blennorrhoea,  etc.,  or  in  phlegmonous  in- 
flammation. Finally,  abnormal  adhesions  may  hinder  the  raising 
of  the  lids. 


*  Practical  Treatise  on  the  Diseases  of  the  Eye,  London,  1854,  pag.  181. 
f  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  73,  und  B.  iv.  2,  pag.  184. 
J  Mackenzie,  1.  c,  pag.  184. 


232  PTOSIS. 

In  niany  individuals  there  is  such  a  superfluity  of  skin  on  the 
upper  lid  that  it  forms  a  fold,  which  may  hang  even  below  the 
edge  of  the  lid.  This  annoyance  may  be  relieved  by  excision  of 
the  superfluous  fold  parallel  to  the  course  of  the  orbicularis  fibres. 
The  same  operative  method  is  applicable  in  cases  where  there 
is  similar  relaxation  and  lengthening  of  the  skin,  caused  by  re- 
peated facial  erysipelas  or  local  infiltration  of  the  lids. 

To  be  distinguished  from  the  class  of  cases  just  described  is 
another,  in  which,  as,  for  instance,  in  partial  congenital  ptosis, 
there  is  neither  a  mechanical  hindrance  to  motion  nor  an  elonga- 
tion of  the  lid.  If,  in  these  cases,  the  patient  be  directed  to  look 
downward,  the  diiference  between  the  two  lids  disappears,  and 
accordingly  an  incision  of  the  skin  would  cause  a  shortening  of 
the  upper  lid,  would  make  the  closure  of  the  eye  difficult,  and, 
upon  looking  downward,  woiild  cause  the  upper  lid  to  fall  behind 
the  other.  Von  Graefe,  therefore,  recommended  in  such  cases  to 
excise  not  the  skin,  but  the  orbicularis  of  the  upper  lid  for  a 
breadth  of  from  7  to  10  mm.,  in  order  that  there  may  be  less 
resistance  to  be  overcome  by  the  weakened  levator.  The  skin  of 
the  lid  is  incised  parallel  to,  and  about  5  mm.  from,  the  edge, 
and  is  dissected  up  on  both  sides  of  the  incision.  The  orbicularis 
is  then  raised  with  the  forceps,  and  a  piece  of  the  proper  size  ex- 
cised. The  wound  is  closed  in  such  a  manner  that  the  upper  and 
lower  remaining  portions  of  the  orbicularis  are  included  in  the 
sutures.* 

A  peculiar  form  of  ptosis  sometimes  occurs  in  connection  with 
contraction  of  the  pupil.  In  a  case  described  by  Horner,!  a  simul- 
taneously occurring  turgescence  of  the  vessels  on  the  affected  half 
of  the  face  was  observed,  which  confirmed  the  suspicion  that  the 
primary  difficulty  was  a  paresis  of  the  cervical  filament  of  the 
sympatlietic  nerve.  It  is  well  known  that  irritation  of  this  nerve 
causes  dilatation  of  the  pupil  and  elevation  of  the  upper  lid,  due 
to  contraction  of  the  smooth  muscular  fibres  in  it. 

Paresis  of  the  orbicularis  generally  occurs  as  one  of  the  symp- 
toms of  facial  paresis.  The  slightest  degree  of  weakness  in  the 
action  of  the  orbicularis  is  manifest  by  the  dripping  of  the  tears. 

*  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  57. 

f  Klin.  Monatsbl.  f.  Augeuheilk.,  1869,  pag.  193. 


ECTROPION.  233 

As  tlie  jjaresis  increases,  the  lids  can  be  only  imperfectly  closed. 
In  extreme  cases  the  upper  lid  is  drawn  up  by  the  levator,  while 
the  under  one  sinks  of  its  own  weight,  its  edge  turned  away  from 
the  eye,  so  that  finally  there  may  be  absolute  ectropion. 

The  continual  gaping  of  the  lids  (lagophthalmus)  exposes  the 
eye  to  all  those  injurious  influences  against  which  it  should  be 
protected  by  the  movements  of  the  lids.  Under  these  circum- 
stances, therefore,  inflammation  of  the  conjunctiva  and  cornea 
develops  very  easily. 

Relaxation  of  the  orbicularis,  independent  of  facial  paresis,  often 
occurs  *in  old  people,  and  causes  likewise  dripping  of  the  tears, 
chronic  conjunctivitis,  and  finally  ectropion  of  the  under  lid. 

ECTEOPION. 

In  acute  blennorrhoea,  especially  in  new-born  infants,  it  often 
happens  that  the  lids  are  everted  accidentally,  or  by  the  strong  con- 
tractions of  the  orbicularis,  and  that  they  cannot  be  replaced  by 
the  persons  present.  The  swollen  mucous  membrane  is  strangu- 
lated by  that  portion  of  the  orbicularis  running  along  the  edge  of 
the  lid,  and  becomes  in  consequence  very  oedematous.  Generally, 
however,  the  everted  lids  may  be  replaced  without  difficulty,  and 
held  in  position  by  a  pressure-bandage.  If  the  swelling  be  so 
great  that  this  cannot  be  done,  the  conjunctiva  should  be  slightly 
scarified.  As  soon  as  the  reposition  of  the  lids  seems  permanent, 
the  local  treatment  of  the  blennorrhoea  is  to  be  begun. 

Ectropion  occurs  oftener  associated  with  chronic  blennorrhoea  of 
the  conjunctiva,  by  which  the  tarsus  gradually  becomes  softened 
and  the  lid  covering  it  becomes  not  only  thicker  but  broader  and 
longer.  So,  too,  the  fibres  of  the  orbicularis  lying  along  the  edge 
of  the  lid  participate  in  the  relaxation  of  the  tissues,  so  tiiat  a 
somewhat  stronger  action  of  the  other  part  of  the  muscle  from  an 
accidental  irritation  or  from  photophobia,  causes  an  eversion  of  the 
edges  of  the  lid.  This  occurs  more  easily,  and  therefore  oftener, 
on  the  under  than  on  the  upper  lid.  This  form  has  been^  called 
sarcomatous  ectropion,  since  the  everted  j)art  of  the  conjunctiva, 
which  is  continually  exposed  to  the  air  and  all  the  injurious  sub- 
stances floating  in  it,  becomes  much  thickened,  and  appears  like  a 
cushion-shaped  swelling.  In  such  a  condition  the  inner  edge  of 
the  lid  is  generally  obliterated,  and  the  outer  one  is  indicated  only 

16 


234 


ECTROPIOlSr. 


Fig.  35. 


-J 


by  a  row  of  poorly  developed  cilia,  while  the  posterior  angle  of 
the  swelling,  where  it  lies  against  the  eyeball,  is  separated  by  a 
distinct  line  from  the  non-everted  part  of  the  conjunctiva. 

In  recent  cases  it  is  often  sufficient,  as  in  acute  blennorrhoea, 
to  make  the  reposition  and  apply  the  pressure-bandage.  If  the 
ectropion  has  developed  gradually,  and  has  already  existed  some 
time,  the  reposition  of  the  lid  is  generally  quite  easy,  but  it  quickly 
falls  back  into  its  abnormal  position.  Still,  in  many  of  these  cases 
a  cure  may  be  effected  by  proper  local  treatment  of  the  conjunctiva 
and  by  the  pressure-bandage. 

If  there  be  perceptible  elongation  of  the  cartilage  and'  lid,  its 
normal  tension    must    be  restored   by  operation.     According    to 

Adams,  this  is  done  by  the  ex- 
cision of  a  wedge-shaped  piece 
from  the  entire  thickness  of  the 
lid.  The  breadth  of  the  piece  to 
be  excised  from  the  edge  of  the 
lid  is  determined  by  measuring 
its  length  from  the  caruncle  to 
the  external  canthus  by  means  of 
a  lead  wire  adapted  to  its  surface 
and  then  comparing  this  with  the 
normal  lid.  Two  incisions  are 
now  made  with  the  knife  through 
the  skin,  as  shown  in  Fig.  35. 
Their  distance  from  each  other  at  the  edge  of  the  lid  is  determined 
by  the  width  of  the  piece  necessary  to  be  excised;  they  converge  as 
they  descend  on  the  cheek  to  a  point  about  10  mm.  below.  The 
piece  to  be  excised  is  then  grasped  by  the  forceps,  one  blade  being 
placed  on  the  skin,  the  other  on  the  conjunctiva.  One  blade  of 
the  straight  scissors  is  then  placed  in  the  wound  and  the  other 
blade  in  the  conjunctival  sac,  and  the  tissues  included  by  them  are 
cut  through  first  on  one  side  of  the  forceps  and  then  on  the  other. 
Thus  there  is  cut  from  the  conjunctiva  also  a  triangular  piece, 
whose  apex  extends  beyond  the  thickened  portion,  nearly  back  to 
the  fornix.  In  order  accurately  to  unite  the  edges  of  the  wound, 
a  straight  pin  is  thrust  through  both  of  them  close  to  the  margin 
of  the  lid  and  just  in  front  of  the  cartilage.  The  edges  are  then 
brought  in  apposition,  and  held  there  by  a  thread,  wound  like  a 


ECTROPION.  235 

figure  8  about  the  two  ends  of  the  pin.  The  lower  part  of  the 
cutaneous  wound  is  united  with  sutures. 

That  place  is  chosen  for  the  operation  at  which  the  ectropion  is 
greatest;  but  if  it  be  uniform  along  the  whole  edge  of  the  lid,  the 
excision  is  made  from  the  middle.  If  the  ectropion  be  principally 
at  the  outer  can  thus,  tiie  operation  sliould  be  tarsorraphy  after 
"VValther's  method.  A  strip  from  4  to  5  mm.  long  and  2  mm. 
broad  is  cut  from  both  the  upper  and  the  lower  lid,  by  incisions 
converging  toward  the  temple,  care  being  taken  that  the  hair 
follicles  belonging  in  the  parts  excised  be  entirely  removed.  The 
freshened  edges  of  the  lids  are  then  united  by  the  pin  and  figure  8 
ligature,  and  thus  the  palpebral  fissure  is  shortened,  the  lids  made 
more  tense  and  caused  to  press  upon  the  eyeball. 

Quite  similar  is  that  form  of  ectropion  which  occurs  in  conse- 
quence ©f  atonia  of  the  orbicularis  muscle  of  the  under  lid  (ectro- 
pium  senile  sive  paralyticum).  The  operations  above  described 
or  Dieifenbach's*  method  maybe  resorted  to  in  these  cases.  Dief- 
fenbach  made,  somewhat  above  the  lower  margin  of  the  orbit  and 
parallel  to  it,  an  incision  through  the  entire  thickness  of  the  lid, 
extending  it  by  a  probe-pointed  knife  through  the  conjunctiva. 
The  conjunctiva  palpebrarum  was  then  drawn  with  a  hook  into 
the  wound,  and  there  so  fastened  with  sutures  that  by  means  of  it 
the  edge  of  the  lid  was  drawn  upward. 

A  similar  effect  is  obtained  by  the  application  of  Snellen's  ectro- 
pion stitch. t  A  silk  thread  is  provided  with  two  needles,  which 
are  thrust  into  the  conjunctiva  behind  the  edge  of  the  lid  at  about 
3  mm.  from  each  other;  they  are  thrust  downward  and  brought 
out  through  the  skin  about  20  mm.  below  the  edge  of  the  lid. 
The  loop  of  the  thread  lies  upon  the  conjunctiva  parallel  to  the 
edge  of  the  lid,  and  the  two  ends  of  the  thread  run  parallel  to 
each  other  under  the  skin.  A  washer  of  soft  glove  leather  is  then 
placed  on  each  end,  and  moderately  strong  tension  being  made, 
they  are  tied  together.  The  washers  prevent  the  threads  from 
cutting  into  the  skin,  and  facilitate  their  removal  if  excessive 
swelling  render  it  necessary.     In  this  way  three  stitches  are  in- 

*  Staub,  Dissert,  de  Blepharoplastice,  Berlin,  1835 ;  Casper's  Wochenschr. 
fiir  die  gesammte  Heilkunde,  i. 

f  Jahresbericht  der  Utrechter  Augenklinik,  1870,  pag.  120. 


236  ENTROPION. 

serted,  one  of  which  it  ife  well  to  place  directly  behind  the  punc- 
tum  lacrymale.  If  the  effect  be  at  first  too  great,  so  as  to  cause 
entropion,  the  irritation  so  excited  may  be  relieved  by  a  few  drops 
of  olive  oil  and  a  pressure-bandage.  After  about  three  days  the 
threads  are  removed,  or  when  they  cause  no  very  great  irritation 
they  may  be  allowed  to  cut  through  of  themselves. 

Ectropion  caused  by  shrinking  of  the  skin  of  the  lid  following 
blepharitis,  is  generally  curable.  Von  Graefe  recommended  in 
these  cases  that  the  rounded  ulcerated  part  of  the  lid  belonging  to 
the  conjunctiva  be  removed  from  one  canthus  to  the  other,  thus 
separating  the  cutaneous  and  conjunctival  surfaces  of  the  lid  for 
a  distance  of  from  13  to  20  mm.  In  order  now  to  change  the 
position  of  the  cutaneous  surface,  sutures  are  placed  through  the 
superficial  fold  of  the  skin  near  the  edge  of  the  lid,  and  these 
are  connected  with  similar  sutures  passed  through  folds  of  more 
distant  parts  of  the  skin  upon  the  forehead  or  cheek,  according 
to  the  direction  in  which  traction  is  to  be  made.  If  the  parts 
be  strongly  drawn  together  by  such  sutures,  a  very  considerable 
change  in  the  ])osition  of  the  edge  of  the  lid  can  be  effected. 

Ectropion  caused  by  extensive  and  deep  penetrating  destruction 
of  the  skin  of  the  lids,  burns,  lupus,  etc.,  and  continuing  after 
comj)lete  healing  of  the  ulceration,  may. often  be  relieved  by  the 
methods  of  operation  above  described ;  more  frequently  they  re- 
quire a  blepharoplastic  operation.  The  same  is  true  of  ectropion 
remaining  after  caries  of  the  edge  of  the  orbit,  by  which  the  fascia 
tarso-orbitalis  is  shortened  and  the  skin  of  the  lid  becomes  ad- 
herent to  the  bone. 

ENTROPION. 

The  turning  inward  of  the  margin  of  the  lid  occurs  in  two 
different  forms  :  the  one  is  caused  by  the  abnormal  action  of  the 
orbicularis,  the  other  by  the  shrinkage  of  the  conjunctiva  and 
tarsus. 

The  first  form  occurs  only  upon  the  lower  lid,  and  generally 
only  in  old  people,  with  relaxed  and  wrinkled  skin.  If  the  entire 
orbicularis  be  relaxed,  and  yet  in  such  a  way  that  the  muscular 
fibres  lying  immediately  along  the  edge  of  the  lid  are  relatively 
the  most  tense,  it  may  happen  that  every  irritation  which  causes 
the  patient  to  shut  his  eyes  tightly  causes  also  a  rolling  inward  of 


ENTEOPION.  237 

the  margin  of  the  lid.  The  entire  margin  of  the  lid  is  not  always 
turned  in,  but  frequently  only  the  temporal  half. 

Foreign  bodies,  all  kinds  of  inflammation  of  the  eyes,  and  slight 
irritation  after  operations  are  the  principal  causes  of  this  kind  of 
entropion.  The  irritation  which  the  cilia  cause  upon  the  con- 
junctiva and  cornea  contributes  of  course  to  perpetuate  the  irregu- 
lar action  of  the  orbicularis  and  to  increase  the  entropion. 

A  slight  traction  upon  the  lid  is  generally  sufficient  to  bring 
the  margin  into  its  normal  position,  but  after  winking  a  few  times 
it  again  rolls  inward.  Since  the  causes  of  this  form  of  entropion 
are  generally  transitory,  the  indication  in  most  cases  is  to  retain 
the  lower  lid  in  its  normal  position  by  a  pressure-bandage  until 
the  cause  of  irritation  (inflammation,  etc.)  is  removed. 

In  many  cases  it  is  sufficient  to  paint  the  under  lid  with  collo- 
dion, which,  by  shrinking,  furnishes  sufficient  traction.  Generally, 
however,  the  skin  of  the  lid  is  so  moist,  from  the  continual  flow 
of  tears,  that  the  collodion  will  not  hold.  In  such  cases  an  ad- 
hesive plaster  bandage  is  more  effective. 

The  skin  of  the  lid  is  'first  made  tense  by  strong  traction,  made 
at  the  same  time  both  outward  and  inward  ;  a  strip  of  adhesive 
plaster  about  1  cm.  broad  and  from  4  to  10  cm.  long  is  then 
fastened  close  under  the  pdge  of  the  lid  and  parallel  to  it,  and  so 
placed  that  being  fastened  first  over  the  region  of  the  lachrymal 
sac  and  then  strongly  stretched,  its  other  end  is  fastened  over  the 
zygomatic  process  upon  the  skin,  which  has  been  slid  inward 
toward  the  outer  angle  of  the  eye.  The  strip  of  adhesive  plaster 
is  then  painted  with  collodion  in  order  to  make  it  impermeable  to 
fluids,  and  still  further  to  increase  its  tension.  If  the  effect  be 
not  yet  sufficient,  a  second  strip  of  plaster  may  be  placed  upon 
the  first  in  a  direction  nearly  perpendicular  to  it,  and  fastened  on 
the  lower  jaw  so  as  to  make  traction  downward. 

If  after  the  removal  of  the  original  irritation  the  entropion 
still  persist,  it  then  becomes  necessary  to  oppose  a  continuous 
counter-tension  to  the  abnormally  increased  tension  of  the  mar- 
ginal portion  of  the  orbicularis.  This  is  done  by  an  operation. 
The  operation  for  the  subcutaneous  formation  of  cicatricial  tissue 
may  be  resorted  to  as  follows : 

A  fold  of  skin  in  the  middle  of  the  lid  and  just  below  its  edge 
is  seized  between  the  thumb  and  first  finger.    Throuo;h  the  base  of 


238 


ENTROPION. 


the  fold,  to  the  median  side  of  the  thumb  and  finger,  a  thread  is 
passed  by  a  curved  needle  thrust  from  below  upward,  and  then  again 
at  a  distance  of  from  2  to  4  mm.  from  above  downward.  A  second 
thread  is  placed  in  the  same  manner  on  the  temporal  side  of  the 
finger.  The  ends  of  each  suture  separately  are  then  brought  to- 
gether and  tied.  The  fold  is  thus  fixed  and  partially  strangulated 
at  two  points  about  1  cm.  distant  from  each  other.  After  from  48 
to  60  hours  the  ligatures  are  removed. 

The  threads  should  not  be  too  fine,  lest  they  cut  through  too 
soon,  and  they  should  not  be  cut  off  too  short,  lest  their  removal 
should  be  made  difficult  by  the  swelling  of  the  skin.  After  some 
days  the  swelling  disappears,  and  gradually  also  the  fold  in  the 
skin,  and  the  cure  is  effected.* 

There  are  other  methods  intended  to  effect  the  same  object,  by 
shortening  the  skin  of  the  lid  either  by  the  excision  of  an  oval 
])iece,  or  according  to  the  following  method  by  Von  Graefe.f 
Three  mm.  under  the  edge  of  the  lid,  and  parallel  to  it,  an  incision 
is  made  through  the  skin,  and  corresponding  in  length  with  the 
palj)ebral  fissure.     A  triangular  piece  of  skin, — Fig.  36, — A,  is 

then  removed ;  the  two  lateral  flaps, 
B  and  C,  are  loosened  somewhat, 
and  are  united  to  each  other  by 
two  or  three  sutures.  The  horizon- 
tal woinid,  which  gapes  but  little, 
is  left  to  cicatrize. 

Entropion  from  the  shrinkage 
of  the  conjunctiva  and  tarsal  carti- 
lage, occurs  in  the  majority  of  cases 
as  the  result  of  trachoma.  The 
entropion  generally  develops  in 
such  a  manner  that  in  the  first 
place  the  inner  edge  of  the  lid  dis- 
appears in  consequence  of  the  conjunctival  shrinkage,  and  thereby 
the  outer  edge,  together  with  the  cilia,  is  turned  toward  the  eyeball. 
In  most  cases  there  is,  especially  upon  the  upper  lid,  at  the  same 
time,  a  shrinkage  and  bowl-shaped  curvature  of  the  cartilage, 


Fio.  30. 


*  Arlt  (nach  Gaillard  unci  Rau),  Augenheilkunde,  iii.  pag.  368. 
f  Arch.  f.  Ophth.,  B.  x.  2,  pag.  223. 


DISTICHIASIS.      BLEPHAROPHIMOSIS. 


239 


involving  either  a  part  or  the  whole  of  the  margin  of  the  lid. 
This  causes  the  margin  of  the  lid  and  the  cilia  to  turn  still  more 
inward.  The  shrinkage  occurring  about  the  roots  of  the  cilia  in- 
terferes with  their  nutrition,  and,  moreover,  gives  a  false  direction 
to  some  of  them,  so  that  thin,  pale,  poorly  developed  hairs  pene- 
trate the  margin  of  the  lid  in  an  abnormal  direction,  sprouting 
more  toward  the  inner  angle  (trichiasis  and  distichiasis).  This 
evil  is  still  further  increased  by  the  fact  that,  in  consequence  of 
the  deformity  of  the  cartilage,  the  marginal  fibres  of  the  orbicu- 
laris rest  upon  a  plane  inclining  downward  upon  the  eyeball,  and, 
moreover,  they  are  constantly  contracted  by  the  irritation  always 
existing  in  such  eyes. 

Simultaneously  there  is  often  a  contraction  of  the  palpebral 
fissure  at  the  outer  canthus  (blepharophimosis),  caused  for  the 
greater  part  by  excoriations  and  subsequent  union  of  the  edges  of 
the  two  lids  at  this  place.  Together  with  the  occurrence  of  the 
blepharoj)himosis  there  is  often  a  shrinkage  of  the  tarsal  portion 
of  the  conjunctiva,  and  as  a  consequence  of  this  the  outer  angle 
of  the  eye  seems  bridged 
over  by  a  fold  of  mucous  ^^' 

membrane,  extending  sev- 
eral millimetres  toward  the 
median  plane. 

If  the  blepharophimosis 
be  extreme,  its  relief  is  often 
a  prerequisite  to  the  per- 
formance of  an  entropion 
operation.  The^  external 
canthus  is  split  in  a  hori- 
zontal direction  with  a 
strong  pair  of  scissors,  one 
blunt  point  of  which  is 
thrust  behind  the  external 
commissure  as  far  as  possi- 
ble into  the  conjunctival  sac. 
To  prevent  the  lids  growing 

together  again,  the  conjunctival  and  cutaneous  edges  of  the  wound 
should  be  united  by  sutures,  as  shown  in  Fig.  37. 

In  the  operative  treatment  of  entropion  with  trichiasis  and  dis- 


240 


ENTROPION. 


tichiasis,  the  result  to  be  aimed  at  is  while  retaining  the  cilia  to 
give  them  a  proper  direction. 

Upon  the  under  lid  this  may  generally  be  done  by  one  of  the 
methods  of  operation  above  described.  They  are,  however,  not 
applicable  to  the  upper  lid.  The  operation  there  is  as  follows.  A 
horn  spatula  is  thrust  under  the  upper  lid,  which  is  then  rolled 
upward  upon  it  until  the  margin  of  the  lid  is  somewhat  raised. 
Then  with  a  small  pointed  knife  an  incision  is  made,  from  a  point 
near  the  punctum  lacrymale  along  the  line  of  the  mouths  of  the 
Meibomian  glands,  the  whole  length  of  the  lid,  and  about  3  or  4 
mm.  deep,  thus  dividing  the  lid  into  two  leaves  (Fig.  38),  the 


Fig.  39. 


inner  one  containing  the  conjunctiva  and  tarsal  cartilage,  with  the 
tarsal  glands,  and  the  outer  one  the  skin,  the  fibres  of  the  orbicu- 
laris and  the  cilia,  together  with  their  bulbs.  The  skin  of  the 
lid  being  now  held  tense,  an  incision  is  made  through  the  outer 
leaf  about  3  or  4  mm.  from  the  edge  of  the  lid,  and  parallel  to 
it.  This  incision  must  be  some  millimetres  longer  at  each  end 
than  the  incision  made  upon  the  edge  of  the  lid.  The  outer  leaf 
of  the  lid  is  thus  transformed  into  a  kind  of  bridge,  entirely  free 
except  at  the  two  ends.  If  this  be  not  the  case,  if  the  bridge,  at 
least  in  its  middle,  be  not  free,  the  knife  is  to  be  introduced  in  the 
upper  wound,  and  its  point  made  to  appear  in  the  lower  one ;  the 
communication  between  the  two  is  then  to  be  enlarged  to  corre- 
spond to  the  lower  wound.     This  being  done,  a  crescent-shaped 


ENTROPION.  241 

piece  of  skin  is  to  be  excised  (Fig.  39).  Its  size  is  to  be  deter- 
mined by  the  degree  of  the  entropion  and  the  amount  of  superflu- 
ous skin.  To  remove  this  piece  a  third  incision  is  made  with  the 
knife,  as  shown  in  Fig.  39.  The  skin  included  between  the  two 
incisions  is  then  grasped  with  the  forceps,  and  dissected  up  from 
the  orbicuhiris  with  the  knife  or  curved  scissors.  If  the  orbicu- 
laris, in  consequence  of  the  habitual  contraction  by  which  it  has 
contributed  toward  maintaining  the  entropion,  be  too  strongly  de- 
veloped, its  marginal  fil)res  may  be  cut  away.  The  wound  in  the 
surface  of  the  lid  is  then  closed  with  sutures,  beginning  in  the 
middle.  When  this  is  done,  the  wound  on  the  margin  of  the  lid 
gapes  widely,  the  outer  leaf  being  drawn  up,  and  in  such  a  posi- 
tion that  the  cilia  are  horizontal,  or  perhaps  directed  somewhat 
upward. 

The  after-treatment  consists  simply  in  cold-water  dressings. 
The  sutures  are  removed  in  from  30  to  36  hours.  The  wound  at 
the  edge  of  the  lid  becomes  covered  with  a  plastic,  yellowish-red 
substance,  and  heals  in  from  3  to  6  days,  without  suppuration. 
The  worst  accident  which  can  happen  is  the  destruction  of  the 
cutaneous  bridge  in  one  or  more  places  by  suppuration.*  In 
order  to  reduce  this  danger  as  much  as  possible,  Von  Graefef  has 
proposed  so  to  modify  the  operation  that  it  is  begun  by  two  ver- 
tical incisions  running  down  to  the  two  angles  of  the  eye,  through 
the  skin  and  orbicularis,  forming  side  boundaries  to  the  part  to  be 
transplanted.  The  intermarginal  incision  is  then  made  just  as  in 
Arlt's  method.  The  outer  leaf  is  then  pushed  up  3  or  4  mm., 
and  sewed  along  the  vertical  incisions.  If  there  be  any  super- 
fluous skin,  an  oval  piece  may  be  excised  from  the  lid.  This 
method  presents  no  essential  advantages.  As  a  general  rule,  per- 
pendicular incisions  upon  the  eyelids  should  be  avoided  as  much 
as  possible. 

The  results  obtained  by  Arlt's  method  are  generally  so  satisfac- 
tory, and  the  operation  is  so  simple,  that  for  the  ordinary  demands 
of  practice  it  may  be  regarded  as  sufficient.  However,  there  is 
one  essential  element  in  these  forms  of  entropion  which  this  oper- 
ation does  not  affect,  namely,  the  bowl-shaped  deformity  of  the 


*  Arlt  (nach  Jasche),  Augenheilkunde,  i.  pag.  146. 
t  Arch.  f.  Ophth.,  B.  x.  2,  pag.  226. 


242  ENTROPION. 

tarsal  cartilages.  Other  operations  have  therefore  been  proposed, 
with  a  view  of  improving  the  shape  of  the  tarsal  cartilages,  and 
in  that  way  healing  the  entropion.  By  the  Crampton- Adams 
method,  the  tarsus  is  divided  by  two  vertical  incisions  made  near 
the  angles  of  the  eye.  These  incisions  are  about  5  mm.  in  length, 
and  their  upper  ends  are  united  by  a  third  incision,  in  the  carti- 
lage, made  from  the  inner  surface  of  the  lid  and  parallel  to  its 
edge.  The  margin  of  the  lid  is  now  everted,  and  held  in  that 
position  by  excising  an  oval  piece  of  the  skin  and  closing  the 
wound  with  sutures.  Care  is  to  be  taken  that  the  vertical  in- 
cisions in  the  cartilage  do  not  reunite  too  quickly.  The  objections 
to  be  made  to  this  method  are  with  reference  to  the  vertical  in- 
cisions in  the  margin  of  the  lid  and  the  incision  of  the  tarsus  on 
the  conjunctival  side.  Among  the  operations  intended  to  improve 
the  form  of  the  cartilage,  that  of  Snellen  deserves  the  preference. 
It  is  as  follows.  In  order  to  control  the  bleeding,  the  upper  lid 
is  strongly  stretched  by  a  horn  spatula  thrust  under  it,  or  it  is 
compressed  by  means  of  Snellen's  blepharospath.*  An  incision 
is  then  made  through  the  skin  the  whole  length  of  the  lid,  2  or  3 
mm.  above  its  edge,  and  parallel  to  it;  the  skin  of  the  lower  lip 
of  the  wound  is  then  somewhat  loosened  and  a  strip  from  the 
marginal  portion  of  the  orbicularis  taken  away  with  the  scissors; 
nearly  the  whole  of  the  tarsus  is  thus  exposed.  With  a  small, 
very  sharp  knife  two  horizontal  incisions  are  made  along  the 
whole  length  of  the  tarsus;  they  converge  downward  toward 
the  conjunctival  surface  of  the  tarsus,  and  thus  a  wedge-formed 
strip  is  cut  away  from  it.  These  incisions  do  not  pass  through 
the  entire  thickness  of  the  tarsus.  Its  conjunctival  surface  is  not 
cut.  A  furrow  being  thus  made  upon  the  surface  of  the  tarsus, 
it,  together  with  the  edge  of  the  lid,  is  then  turned  outward  in 
the  following  manner.  The  skin  of  the  lid  is,  in  the  first  place, 
slid  upward,  and  in  that  way  the  upper  margin  of  the  tarsus 
is  exposed.     A  silk  thread,  provided  with  two  needles,  is  then 

*  A  kind  of  forceps,  one  arm  of  which  is  a  metal  plate,  corresponding  in 
size  and  shape  to  the  upper  lid,  under  which  it  is  thrust.  The  other  arm  of 
the  forceps  is  roundish,  and  so  curved  that  it  covers  the  edge  of  the  plate,  with 
the  exception  of  that  part  which  corresponds  with  the  edge  of  the  lid.  The 
forceps  may  be  clamped  together  by  a  screw,  and  in  that  way  all  annoying 
hemorrhage  prevented. 


ENTEOPION.  243 

passed  by  means  of  one  of  the  needles  through  the  upper  margin 
of  the  tarsus ;  the  two  ends  of  the  thread  are  then  brought  down 
over  the  anterior  surface  of  the  tarsus,  are  passed  through  the  lower 
lip  of  the  wound,  and  are  brought  out  just  above  the  roots  of 
the  cilia,  at  a  distance  of  about  3  or  4  mm.  from  each  other.  In 
order  to  bend  the  tarsus  outward  and  to  turn  the  edge  of  the  lid 
upward,  it  is  necessary  to  draw  upon  these  threads  quite  strongly 
and  tie  them  together;  this  may  easily  cause  them  to  cut  through 
the  skin.  In  order  to  avoid  this  evil,  it  is  well  to  place  a  washer 
of  glove  leather  upon  each  end  of  the  thread,  just  as  in  the  ectro- 
pion operation  (see  page  235.)  Nevertheless,  necrosis  of  the  skin 
of  the  lid  is  often  caused  by  the  pressure.  The  presence  of  the 
washers  facilitates  the  removal  of  the  threads  on  about  the  second 
day. 

Three  sutures  are  placed  in  this  manner.  It  is  unnecessary  to 
close  the  wound  in  the  skin  by  sutures.  The  ends  of  the  three 
sutures  before  mentioned  are  fastened  with  adhesive  plaster  above 
the  eyebrow  upon  the  forehead,  and  in  this  way  the  two  lips  of 
the  "wound  are  held  in  apposition.  Since  there  is  no  excision  of 
the  skin  connected  with  this  operation,  it  may  without  any  injury 
be  repeated  if  the  effect  be  insufficient  or  if  relapses  occur  in  the 
further  course  of  the  trachoma. 

If  not  the  entire  margin  of  the  lid  but  only  a  part  of  the  cilia 
be  turned  inward,  or  if  the  condition  in  general  be  so  slight  that 
a  serious  operation  does  not  seem  to  be  indicated,  the  affected  place 
upon  the  margin  of  the  lid  may  be  cauterized  with  concentrated 
sulphuric  acid. 

If  upon  an  otherwise  normal  lid  only  a  single  cilium,  or  a  very 
small  number  of  them,  turn  inward  and  irritate  the  cornea,  they 
may  be  restored  to  their  normal  position  in  the  following  manner. 
Both  ends  of  a  very  fine  thread  or  a  sufficiently  long  hair  are 
placed  together  and  passed  through  the  eye  of  a  needle  so  as  to 
form  a  loop.  The  needle  is  then  inserted  just  at  the  root  of  the 
falsely  placed  cilium,  and  is  brought  out  exactly  in  the  line  of  the 
normal  cilia.  The  thread  is  then  drawn  so  far  through  that  only 
a  small  loop  protrudes  at  the  place  of  entrance,  and  in  this  the 
abnormal  cilium  is  placed  with  the  forceps.  The  loop  is  then 
drawn  through  so  that  the  point  of  the  cilium  is  brought  to  view 
between  the  normal  cilia.     If  the  cilium  do  not  fall  out  too  soon, 


244  DISTICHIASIS,      SYMBLEPHARON. 

the  position  and  direction  of  its  follicle  may  be  in  this  way  per- 
manently changed.  This  method  was  described  by  Celsus  as 
"  illaqueatio." 

Occasionally,  in  patients  who  are  annoyed  by  a  sensation  as  of  a 
foreign  body  in  the  eye,  there  may  be  found,  either  with  the  naked 
eye  or  by  the  help  of  a  lens,  a  number  of  very  fine  cilia  (strongly 
developed  lanugo),  which,  with  their  points,  touch  the  caruncula 
lacrymalis.     Epilation  is  the  only  remedy. 

Distichiasis  congenita  is  very  rare.  In  this  condition  the  cilia 
at  the  outer  edge  of  the  lid  are  normally  developed,  but  from  the 
intermargin^l  part,  near  the  mouths  of  the  tarsal  glands,  there 
springs  a  second  row  of  cilia  which  lean  against  the  eyeball.  In 
many  cases  there  exist  still  other  congenital  anomalies;  for  in- 
stance, in  one  case  which  I  observed  there  was  epicanthus  and 
bilateral  ptosis  congenita ;  in  another  case  I  found  a  cleft  in  the 
soft  palate. 

Amnion  has  given  the  name  epicanthus  to  that  condition  in 
which  there  is  a  redundancy  of  skin  upon  the  bridge  of  the  nose, 
and  as  a  consequence  the  inner  canthus  is  covered  by  a  vertical 
fold.  It  occurs  only  when  the  bridge  of  the  nose  is  very  flat,  and 
in  its  highest  grades  is  generally  associated  with  congenital  ptosis. 
If  it  seem  desirable  to  relieve  the  condition  by  operation,  it  may 
be  done  by  the  excision  of  an  elliptical  piece  from  the  superfluous 
skin  on  the  bridge  of  the  nose. 

Congenital  cleft  (coloboma)  of  the  upper  lid  has  been  observed 
generally  associated  with  other  congenital  anomalies.  If  the  cleft 
be  so  deep  that  it  requires  to  be  closed  by  an  operation,  its  edges 
are  to  be  freshened  and  then  united  with  sutures. 

SYMBLEPHARON. 

Symblepharon  is  the  union  of  the  inner  surface  of  the  lid  with 
the  eyeball,  following  destruction  of  the  conjunctiva.  Burns  with 
hot  metal,  concentrated  mineral  acids,  lime,  and  unskilful  cauteri- 
zations with  nitrate  of  silver  are  the  usual  causes.  It  very  seldom 
follows  wounds  made  with  sharp  instruments. 

Since  it  is  almost  always  due  to  an  accidental  spurting  of  the 
caustic  in'to  the  eye,  the  scleral  and  palpebral  conjunctiva  are 
generally  simultaneously  destroyed  and  the  cornea  involved  in 
the  injury 


SYMBLEPHARON.  245 

The  immediate  consequence  of  the  injury  is  generally  a  severe 
traumatic  keratitis  and  conjunctivitis,  in  which,  during  the  acute 
stage,  the  palpebral  fissure  is  kept  closed  either  by  the  swelling  of 
the  lids  or  by  the  irritation.  During  this  time  adhesions  form 
between  the  two  raw  surfaces  of  the  conjunctiva  or  between  the 
inner  surface  of  the  lid  and  the  injured  cornea.  These  adhesions 
remain,  although  they  become  somewhat  stretched  when  motion 
is  restored. 

The  form  and  extent  of  the  adhesions  vary  according  to  the 
injury  to  the  conjunctiva.  The  destruction  generally  extends  back 
to  the  fornix,  so  that  the  lids  adhere  to  the  eyeball  throughout  a 
great  extent  of  surface.  Often  in  such  cases,  when  both  lids  are 
involved,  the  palpebral  fissure  becomes  shortened,  and  the  mobility 
of  the  lids,  as  well  as  of  the  eyeball,  is  limited. 

In  other  cases  the  adhesion  of  the  two  conjunctival  surfaces 
extends  forward  from  the  fornix  to  the  edge  of  the  lid  in  an 
oblique  direction ;  a  probe  can  then  be  thrust  for  a  greater  or 
less  distance  under  the  adhesion  till  its  point  reaches  the  end  of 
the  pocket  thus  formed  by  the  symblepharon. 

Finally,  it  sometimes  happens  that  the  adhesions  do  not  extend 
back  quite  to  the  fornix,  but  bridge  it  over,  so  that  a  jDrobe  can  be 
passed  under  it. 

In  consequence  of  these  adhesions  the  movements  of  both  the 
lids  and  eyeball  are  impeded.  This  gives  to  the  patient  a  sen- 
sation of  traction,  and  where  the  eye  still  possesses  vision  it  causes 
diplopia  corresponding  to  the  defect  of  motion. 

The  removal  of  the  symblepharon  may  be  indicated  either  to 
restore  the  function  of  the  eye,  or,  where  that  cannot  be  done,  to 
render  possible  the  use  of  an  artificial  one. 

If  the  cornea  be  entirely  destroyed  by  the  injury  which  caused 
the  symblepharon  and  there  be  no  desire  to  wear  an  artificial  eye, 
there  is  no  indication  for  an  operation.  If  a  useful  degree  of 
vision  still  remain,  or  if  in  case  of  extensive  corneal  opacities  it 
may  be  re-established,  for  instance,  by  an  iridectomy,  the  removal 
of  the  symblepharon  should  be  undertaken  when  the  adhesions 
do  not  involve  more  than  half  the  upper  or  lower  lid.  More 
extensive  adhesions  cannot  be  relieved,  not  from  any  difficulty  in 
dividing  them,  but  because  of  the  impossibility  of  preventing 
their  reunion.    After  the  division  of  the  adhesions  the  two  wounded 


246  SYMBLEPHAROX. 

surfaces — that  of  the  lid  and  that  of  the  sclera — lie  in  apposition, 
and  they  are,  moreover,  continuous  with  each  other  when,  as  is 
usually  the  case,  the  adhesions  extend  back  to  the  fornix  instead 
of  bridging  it  over,  as  we  have  said  occasionally  happens. 

The  simple  contact  of  the  two  wounded  surfaces  would  cause 
no  difficulty.  The  natural  movements  of  the  eye,  or  a  frequent 
lifting  of  the  lid  from  the  eyeball,  are  sufficient  to  prevent  reunion. 
But  if  the  wounded  surfaces  are  continuous  with  each  other  across 
the  fornix,  a  cicatricial  process  begins  there  which  gradually  but 
surely  brings  the  eye  back  to  its  old  condition.  The  important 
thing  is  to  prevent  the  two  surfaces  from  being  united  by  cicatricial 
tissue  at  the  fornix.  An  eifort  should  be  made  to  bridge  over 
the  fornix.  This  is  done  by  passing  a  lead  wire,  by  means  of  a 
curved  needle,  through  the  deepest  part  of  the  syrablepharon  and 
allowing;  it  to  lie  there  till  a  cicatrix  has  formed  about  it.  This 
always  requires  several  weeks  or  months,  and  occasionally  nothing 
more  is  accomplished  than  that  the  wire  gradually  cuts  through, 
and  the  cicatricial  tissue  closes  up  after  it. 

Arlt  has  proposed  a  good  method  by  which  the  conjunctiva  is 
united  by  sutures  at  the  fornix.  If  the  adhesions  be  not  too  wide, 
it  is  easy  after  dividing  them  to  sew  up  the  wound  upon  the 
eyeball  by  passing  sutures,  by  means  of  a  curved  needle,  through 
the  connective  tissue  and  subconjunctival  fascia  from  one  lip  of 
the  wound  to  the  other.*  If  in  doing  this  the  conjunctiva  be 
drawn  too  tense,  so  that  the  sutures  threaten  to  cut  through,  it  is 
well  to  relieve  the  tension  by  lateral  incisions,  such  as  are  made  in 
plastic  operations. 

In  those  cases  in  which  an  adhesion  has  formed  in  a  slanting 
direction  from  the  fornix  up  to  the  margin  of  the  lid,  it  is  well, 
after  separating  the  adhesion,  to  close  the  wound  at  the  fornix, 
since  it  is  from  that  point  that  the  cicatrix  re-forms. 

A  bridge-like  symblepharon,  which  does  not  extend  down  into 
the  fornix,  may  be  divided  upon  a  director  which  has  been  passed 
under  it.  A  suture  is,  under  these  circumstances,  not  absolutely 
necessary,  but  for  safety  the  wound  in  the  conjunctiva  sclerse  may 
be  closed  with  stitches. 

After  extensive  burns  u^^on  the  face  in  the  neighborhood  of  the 

*  Prager  Vierteljahrsschrift,  1854,  und  Augenkrankheiten,  iii.  pag.  375. 


'  ANCHYLOBLEPHAEON.  247 

eyelids,  and  often,  too,  after  ulceration  by  lupus  in  this  region, 
there  may  be  a  total  occlusion  of  the  palpebral  fissure  (anchylo- 
blepharon).  No  trace  of  the  eyelids  is  left ;  the  eyeball  is  covered 
by  tightly  stretched  cicatricial  tissue,  through  which  it  can  some- 
times be  recognized  by  its  movements,  and  through  which,  too,  it 
may  receive  a  sensation  of  light.  No  improvement  can  be  made 
by  an  operation,  since  in  such  cases  the  cornea  is  either  destroyed 
or  united  with  the  cicatricial  tissue. 

BLEPHAEPOLASTIC   OPEEATIONS. 

The  indication  for  a  blepharoplastic  operation  is  given  by  an 
extensive  loss  of  substance  from  the  eyelids.  In  most  cases  its 
object  is  to  cover  the  loss  of  substance  remaining  after  the  extir- 
]>ation  of  tumors  upon  the  lids,  or  to  relieve  an  ectropion  which 
is  due  to  cicatricial  contraction  after  ulcerations  or  other  loss  of 
substance. 

The  most  important  points  to  be  observed  in  doing  blepharo- 
plastic operations  are  the  following  : 

1.  A  normal  part  of  the  defective  lid  ought  never  to  be  sacri- 
ficed, because  the  new-formed  part  of  the  lid  can  be  moved  only 
by  what  remains  of  the  original  one. 

2.  Healthy  conjunctiva,  even  when  in  a  state  of  inflammatory 
irritation,  ought  never  to  be  cut  away.  Where  possible,  it  is  to 
be  used  for  lining  the  edge  of  the  new-formed  lid. 

3.  The  piece  of  skin  to  be  transplanted  must  not  be  taken  from 
too  distant  a  part.  It  must  be  so  cut  that  the  flap  is  neither  too 
scant  nor  too  long,  in  which  latter  case  it  will  roll  together. 

4.  Finally,  it  is  advisable  so  to  plan  the  operation  that  the 
defect  caused  by  cutting  out  the  flap  does  not  need  to  heal  by  gran- 
ulation, since  otherwise,  in  consequence  of  the  cicatricial  contrac- 
tion near  the  transplanted  flap  and  upon  its  posterior  surface,  a 
deformity  is  caused  in  the  new  lid.  The  hope  expressed  by  Dief- 
fenbach,  that  the  cicatricial  contractions  under  and  near  the  flap 
would  neutralize  each  other,  has  not  been  realized. 

With  these  rules  in  mind,  the  plan  for  each  separate  operation 
is  to  be  made,  since  the  individual  variations  are  so  great  that 
almost  every  case  requires  some  peculiar  arrangement  of  the  in- 
cisions. It  would  be  exceeding  the  limits  prescribed  in  this  work 
to  take  up  this  subject  exhaustively.     It  will  suffice  to  describe 


248  BLEPHAROPLASTIC  OPERATIONS. 

the  original  method  of  Dieffenbach,  since  with  slight  modifica- 
tions it  is  suitable  for  the  majority  of  cases. 

In  the  case  of  the  under  lid,  the  extirpation  of  the  scar  or  tumor 
is  so  made  that  a  triangular  loss  of  substance  remains.     Its  base 

a  c  (Fig.  40)  is  turned  toward  the  lid, 
Fig.  40.  ... 

its  apex,  h,  is  directed  downward.     To 

'/  replace  the  defect  a  b  c,  Dieffenbach 
made  the  flap  e  d  e,  which  he  dissected 
up,  leaving  the  fatty  tissue ;  and  after 
stopping  the  hemorrhage  and  cleans- 
ing the  previously  exposed  triangular 
space,  he  moved  the  flap  over,  so  that 
its  upper  border  occupied  the  place  of 
the  margin  of  the  lid,  or  was  joined  to  it  in  case  the  margin  still 
remained  ;  the  median  margin  of  the  flap  was  thus  brought  over 
to  the  line  ab.  The  flap  is  stitched  first  at  the  inner  angle  of  tlie 
eye.  Its  upper  margin  is  then  stitched  to  the  conjunctiva,  or  to 
the  margin  of  the  lid,  if  that  be  still  present;  the  wound  at  a  6 
is  closed  in  the  same  way  after  its  median  lip  has  been  dissected 
upward  somewhat  from  the  subcutaneous  tissue. 

There  remains  now  on  the  temporal  side  of  the  transplanted 
flap  a  defect  which  is  left  to  cicatrize,  but  which,  without  any 
injury,  and  indeed  with  advantage  to  the  flap,  may  be  somewhat 
reduced  by  sutures  placed  at  the  angle  d. 

Szymanowski*  proposed  to  give  to  the  transplanted  flap  the 
form  c  h  e.  The  advantages  are :  1,  that  the  flap  b  c  h  e  is 
longer,  and  even  after  its  contraction  fills  the  space  a  b  c  with- 
out causing  tension ;  2,  that  its  upper,  broader  margin  may  be 
stitched  out  beyond  the  outer  angle  of  the  eye,  thus  making  the 
best  possible  provision  against  its  sinking  downward ;  and,  3, 
that  the  defect  may  be  more  easily  closed  from  the  acute  angle  h. 
Blepharoplastic  operations  are  much  more  difficult  upon  the 
upper  lid.  The  simplest  and  best  method  is  that  of  Dieffenbach, 
for  which  Szymanowski  also  recommended  his  modification  of  the 
acute-angled  flap.  The  defect  ab  c  (Fig.  41)  is  covered  by  a  flap, 
b  G  d  e,  borrowed  from  the  temple.  Since  this  is  considerably 
broader  than  the  defect,  its  union  may  be  insured  by  sutures,  not 

*  Handbuch  der  operativen  Chirurgie,  i.  pag.  220  u.  folg. 


BLEPHAEOPLASTIC   OPERATIONS. 


249 


only  along  the  line  ab  but  also  at  d.     Moreover,  the  whole  defect 
may  be  covered  by  sutures  from  f  to  d  and  from  e  to  d.     The 

Fig.  41. 

d 


hurtful  influence  which  the  cicatricial  contraction  at  this  place 
may  exert  upon  the  form  of  the  new  lid  is  thereby  diminished, 
and  at  the  same  time  the  sutures  at  d  act  to  prevent  both  the 
transplanted  flap  from  drawing  upward  and  the  lower  lid  from 
sinking  downward. 

Fig.  42. 


When  this  method  is  not  practicable,  the  transplantation  of  an 
oval  or  tongue-shaped  flap  from  the  temple  or  forehead  may  be 
undertaken,  as  shown  in  Fig.  42.  This  method,  first  proposed 
by  Fricke,  has  the  disadvantage  that  the  newly  made  defect  can- 
not,  on  account  of  its  oval  shape,  be  entirely  closed.  Mofeover, 
the  oval  flap  has  a  special  tendency,  on  account  of  the  cicatricial 
contraction  on  its  under  surface,  to  draw  itself  concentrically 
together  into  a  spherical  mass.  If  the  flap  be  very  long  and 
tongue-shaped,  there  is  danger  of  gangrene  occurring  at  its  point. 

Loss  of  substance  at  the  inner  angle  of  the  eye  may  be  replaced 
by  transplantation  from  the  skin  of  the  nose,  or,  if  that  be  not 
practicable,  from  the  forehead.  With  loss  of  substance  at  the  outer 
angle  of  the  eye  the  closure  of  the  wound  is  not  difficult,  as  the 
skin  in  this  region  is  so  loosely  attached. 

In  many  cases  the  blepharoplastic  methods  above  described 
may  be  dispensed  with,  and  small  pieces  of  skin  transplanted  from 
distant  parts  of  the  body,  or,  indeed,  taken  from  other  persons. 
This  method  has  before  been   practised  in  surgery  for  healing 

17 


250  TEANSPLANTATION   OF  SKIN. 

ulcers,  closing  losses  of  substance  after  burns,  etc.  For  replacing 
lost  tissue  upon  the  eyelid  one  may  proceed  as  follows,*  A  small 
fold  of  skin  is  raised  upon  the  forearm  with  the  thumb  and  fore- 
finger ;  its  base  is  then  transfixed  with  a  knife,  and  separated  at 
one  end ;  it  is  then  grasped  with  the  forceps,  and  the  whole  fold 
cut  away  with  a  ])air  of  scissors  curved  on  the  flat.  In  this  way 
a  small  piece  is  obtained,  measuring,  after  its  contraction,  from  3 
to  8  mm.  in  every  direction.  This  is  placed  upon  the  raw  surface 
and  carefully  spread  out  with  the  probe.  The  wound  is  covered 
as  fully  as  possible  with  a  thick  mosaic  of  such  little  pieces,  10  to 
'20  in  number,  according  to  the  size  of  the  defect. 

The  entire  wound  is  then  covered  with  gold-beater's  skin, 
which  is  sufficiently  transparent  to  allow  the  observation  of  the 
transplanted  pieces.  Finally,  to  insure  perfect  rest,  both  eyes 
are  closed  with  a  pressure-bandage,  which  is  allowed  to  remain 
unchanged  for  24  hours. 

The  result  of  the  operation  may  be  predicted  after  the  very 
first  day,  by  the  changes  in  color  perceptible  through  the  gold- 
beater's skin.  Those  little  pieces  M'hich  adhere  show,  after  36  to 
48  hours,  a  bright  redness,  which  gradually  grows  darker.  Even 
if  some  of  them  retain  their  pale-yellow  color,  become  surrounded 
by  a  brownish-black  zone,  and  finally  mummify,  it  may  still  be  the 
case  that  only  the  epidermis  has  died,  while  the  cutis  has  adhered. 
There  is  nothing  to  prevent  substituting  new  pieces  for  those 
which  have  died,  and  this  is  advisable  in  order  to  avoid  the  hurt- 
ful influence  which  continual  suppuration  may  exert  upon  the 
living  pieces. 

If  this  method  be  determined  on,  for  instance,  in  a  cicatricial 
ectropion  which  otherwise  would  require  a  blepharoplastic  oper- 
ation, the  first  step  is  to  detach  the  lid  from  the  cicatrix  by  an 
incision,  if  possible,  1|  or  2  cm.  from  the  edge  of  the  lid.  The 
cicatrix  is  to  be  dissected  up  till  the  ectropion  is  fully  relieved 
and  the  palpebral  fissure  can  be  closed  without  any  difficulty. 
This  last  is  the  most  important  point  in  the  operation,  and,  no 
matter  how  large  the  wound,  the  lids  must  be  allowed  to  close 
perfectly. 


*  L.  de  Wecker,  De  la  Greffe  dermique  en  Chirurgie  oculaire,  Annales 
d'Oculistique,  Juillet   et  Aout,  1872. 


TRANSPLANTATION  OF   SKIN.  251 

The  margins  of  the  two  lids  are  then  freshened  at  several 
points  and  united  with  sutures.  The  covering  of  the  wounded 
surface  is  not  to  be  undertaken  until  its  edges  have  flattened 
down  and  free  suppuration  is  established,  on  the  seventh  or  eighth 
day.  The  transplantation  effects  an  absolute  cure  of  the  extensive 
wounded  surface,  which  otherwise,  by  its  cicatricial  contraction, 
would  have  been  sure  to  cause  ectropion  again.  When  the  cure 
is  finally  made  sure,  the  last  step  is  to  re-open  the  palpebral  fissure 
which  had  been  closed  by  the  tarsorraphy. 

Transplantation  is  resorted  to  in  a  similar  manner  in  cases  in. 
which  there  has  been  extensive  loss  of  substance  on  the  lids,  in. 
consequence  of  wounds,  burns,  or  operations. 


DISEASES  OF  THE  CONJUNCTIVA. 


Although  in  describing  the  diseases  of  the  conjunctiva  they 
are  divided  into  certain  groups,  it  must  be  remembered  that  in 
practice  the  boundaries  of  these  groups  are  very  indistinct.  Cases 
often  occur  which  may  properly  enough  be  classed  in  either  one 
group  or  another.  For  instance,  what  was  originally  a  simple 
catarrhal  conjunctivitis  may,  by  neglect  and  continual  irritation, 
pass  into  a  chronic  blennorrhoeal  or  trachomatous  state.  Phlyc- 
tenular conjunctivitis  about  the  margin  of  the  cornea  presents 
another  example  of  this  kind.  One  often  sees  an  acute  catarrhal 
or  mild  blennorrhoeal  swelling  occur  simultaneously  with,  or  some- 
what later  than,  the  phlyctenules.  Conjunctival  diseases  of  vari- 
ous kinds  often  present  a  peculiar  appearance,  differing  from  their 
typical  forms  in  the  fact  that  the  conjunctival  follicles  are  abnor- 
mally prominent. 

These  various  encroachments  of  one  form  of  disease  upon  the 
other,  only  prove  that  no  classification  must  be  too  dogmatically 
adhered  to,  as  it  cannot  hold  good  for  all  cases. 

HYPEREMIA    OF    THE   CONJUNCTIVA. 

Acute  hypersemia  of  the  conjunctiva  either  passes  quickly  away 
or  is  the  precursor  of  an  inflammatory  condition.  A  slowly 
developed  chronic  hypersemia,  or  one  remaining  after  a  previous 
conjunctivitis,  may,  on  the  contrary,  remain  unchanged  a  long 
time.  It  is  characterized  by  a  stronger  injection  of  the  visible 
vessels,  especially  those  of  the  conjunctiva  palpebrarum;  a  hyper- 
semia of  the  conjunctiva  scleras  and  a  redness  of  the  margins  of 
the  lids  generally  exist  at  the  same  time.  There  is  frequently  a 
slight  swelling  of  the  conjunctival  follicles,  especially  on  the  tem- 
poral half  of  the  lower  lid.  Anomalies  of  secretion  are  absent, 
or  there  may  be  slightly  increased  lachrymation  and  secretion 
of  mucus,  which,  during  the  night,  glues  the  cilia  together  in 
bundles. 

252 


HYPEE^MIA    OF   THE    CONJUXCTIVA.  253 

The  annoyances  consist  in  sensations  of  burning,  itching,  prick- 
ing, etc.,  which  increase  tlie  more  the  eyes  are  used,  especially 
by  artificial  light.  The  heat  from  the  lamp  aggravates  these 
symptoms. 

In  many  cases  the  feeling  of  pressure,  pricking  in  the  eyes, 
etc.,  which  comes  on  during  work,  is  so  annoying  that  the  condi- 
tion resembles  asthenopia;  consequently  we  may  speak  of  conjunc- 
tival as  well  as  of  accommodative  or  muscular  asthenopia.  The 
diagnosis  is  generally  made  certain  by  the  objective  symptoms. 
Nevertheless,  I  have  seen  some  cases  in  which  the  conjunctiva 
showed  no  abnormity,  but  in  which  there  was  asthenopia,  which 
was  certainly  of  neither  an  accommodative  nor  a  muscular  nature, 
while  the  absence  of  all  other  nervous  disturbances  excluded  the 
idea  of  nervous  asthenopia;  moreover,  the  symptoms  of  irrita- 
tion were  not  those  so  often  occurring  in  connection  with  myopia. 
The  evidence  that  in  these  cases  a  conjunctival  affection  was  the 
primary  one,  lay  in  the  fact  that  after  reading  a  few  minutes,  pain 
occurred,  with  evident  hyperaemia  of  the  conjunctiva  and  copious 
secretion  of  tears,  which  made  work  impossible. 

The  treatment  based  upon  this  idea  consisted  at  first  in  pen- 
cilling with  a  3  per  cent,  solution  of  sulphate  of  zinc,  and  later 
with  dilute  tincture  of  opium.  It  proved  efficacious,  thus  con- 
firming the  diagnosis. 

The  causes  of  chronic  conjunctival  hyperaemia  often  lie  in  a 
continuous  exposure  to  hurtful  influences,  such  as  confined  impure 
air,  smoke,  dust,  etc.,  or  in  straining  the  eyes  by  working  with 
insufficient  illumination. 

The  treatment  consists  in  the  first  place  in  removing  as  much 
as  possible  the  causes,  not  forgetting  the  possible  co-existence  of 
accommodative  or  muscular  asthenopia.  The  local  treatment  con- 
sists in  the  use  of  cooling  and  slightly  astringent  applications,, 
cold  baths  for  the  eyes,  cold  dressings,  or  the  eye-douche.  Among 
the  astringent  eye-waters,  the  best  are  J  per  cent,  solutions  of 
either  sulphate  of  zinc  or  neutral  acetate  of  lead.  In  cases  of 
very  marked  hyperoemia  it  is  often  M^ell  to  apply  a  2  or  3  per 
cent,  solution  of  either  of  these  remedies  to  the  conjunctiva  with 
a  pencil,  and  immediately  wash  away  the  surplus  with'  water. 
In  conjunctival  asthenopia  it  is  often  well,  toward  the  end  of 
the  treatment,  to  employ  dilute  tincture  of  opium. 


k 


254  SIMPLE   CONJUNCTIVITIS. 


SIMPLE   CONJUNCTIVITIS. 

Conjunctivitis  exists  whenever,  in  addition  to  swelling  and  red- 
ness, there  is  a  copious  abnormal  secretion  from  the  conjunctiva. 
The  redness  is  characterized  by  a  dilatation  both  of  the  larger  ves- 
sels and  the  capillaries,  and  appears  therefore  as  a  net-work  in  the 
fornix,  where  the  larger  vessels  and  their  first  branches  lie,  but  in 
the  tarsal  part  it  is  a  more  uniform  bright  red.  The  vessels  of 
the  conjunctiva  sclera  are  often  also  dilated.  These  vessels  run 
from  the  fornix  toward  the  cornea,  and  form  with  their  branches 
a  coarse  net-work,  distinctly  visible  against  the  white  background 
of  the  sclera.  In  more  severe  cases  the  anterior  ciliary  vessels 
may  also  be  injected ;  they  form  then  a  rosy-red  border  of  short, 
thickly-set  vessels  radiating  about  the  cornea.  Often  there  are 
also  slight  ecchymoses  upon  the  scleral  conjunctiva.  After  it  has 
continued  a  long  time,  the  redness  shows  a  tendency  to  concentrate 
at  the  angles  of  the  eyes  and  along  the  edges  of  the  lids. 

The  swelling  is  generally  not  very  great,  is  mostly  limited  to 
the  conjunctiva  of  the  lids,  is  greatest  near  the  fornix,  and  loss 
upon  the  tarsal  part.  In  very  acute  cases,  or  in  very  old  people 
with  relaxed  conjunctivae,  a  serous  infiltration  occurs  in  the  sub- 
conjunctival tissue  of  the  sclera,  making  it  still  more  easy  to  slide 
the  vessels  upon  the  sclera  than  in  the  normal  condition. 

AVhen  the  process  is  long  continued,  a  hypertrophy  of  the  papil- 
lary layer  of  the  mucous  membrane  may  take  place,  giving  to  the 
surface  a  velvety,  dark-red  ajipearance. 

It  is  only  in  very  acute  cases  that  the  subcutaneous  connective 
tissue  of  the  lids  participates  in  the  process.  There  is  then  great 
swelling  of  the  fornix  and  conjunctiva  sclerse  with  copious  muco- 
purulent secretion,  a  condition  closely  resembling  the  blennorrhoeal 
affection. 

The  abnormal  secretion  appears  first  as  a  copious  flow  of  tears 
containing  formed  elements,  such  as  epithelial  cells,  mucus,  and 
fat-corpuscles,  partly  to  be  seen  only  microscopically,  partly  oc- 
curring in  the  form  of  grayish-yellow  flakes  or  threads ;  these  last 
are  found  principally  in  the  fornix,  where  the  secretions  are  rolled 
together  by  the  movements  of  the  eye.  The  secretion  dries  and 
forms  crusts  upon  the  lachrymal  caruncle  and  cilia;  it  often  so 
accumulates  during  sleep  as  to  glue  the  eyelids  together.      If  the 


SIMPLE    CONJUNCTIVITIS.  255 

secretion  be  so  copious  tliat  the  tears  drip  continually  over  the  lid, 
an  excoriation  of  the  skin  may  result. 

The  secretion  becomes  infectious  as  soon  as  it  assumes  a  muco- 
purulent character;  but  even  in  the  less  severe  forms  it  is  advisa- 
ble to  regard  it  as  possibly  infectious,  and  to  observe  the  proper 
precautions. 

The  subjective  symptoms  consist  principally  in  a  sensation  of 
pressure  and  pricking,  as  if  sand  or  a  foreign  body  were  in  the 
eye,  or  in  itching,  burning,  and  heaviness  of  the  eyelids,  as  when 
drowsy,  etc.  Associated  with  these  symptoms  there  is  often  a 
sensitiveness  to  light,  especially  to  artificial  illumination,  with  in- 
ability to  use  the  eyes  for  work,  and  occasional  indistinctness  of 
vision.  These  disturbances  of  vision  are  evidently  caused  by  thin 
films  of  mucus  which  occasionally  form  over  the  cornea;  after 
their  removal  vision  is  as  good  as  ever.  It  is  probable,  too,  that 
still  another  symptom,  which  is  especially  frequent  in  chronic  cases, 
namely,  the  appearance  of  colored  rings  about  the  flame  of  a  lamp, 
is  likewise  due  to  the  refraction  caused  by  a  thin  film  of  abnormal 
secretion  upon  the  cornea. 

Often,  after  all  the  actual  symptoms  of  conjunctivitis  have  dis- 
appeared, this  single  annoyance  remains, — that  the  patient  uj^on 
waking  finds  it  is  only  with  an  unpleasant  sensation  of  ])ain  that 
he  can  open  his  eyes ;  this  is  probably  because  during  sleep,  and 
favored  by  the  perfect  rest  in  that  condition,  and  on  account  of 
some  anomaly  in  the  secretions  of  the  mucous  membrane,  a  rela- 
tively too  strong  adhesion  between  the  lid  and  the  eyeball  occurs. 

The  causes  of  conjunctivitis  are  partly  general  and  ])artly  local. 
Often  it  is  associated  with  other  catarrhal  processes,  as,  for  instance, 
with  nasal  catarrh,  or  as  a  part  of  a  general  catarrhal  affection,  as 
in  the  exanthematous  diseases,  measles,  scarlatina,  etc.  ;  or  it  may 
occur  as  an  independent  disease  following  colds  or  injuries.  Trau- 
matic conjunctivitis,  for  instance,  when  it  is  neglected  or  exposed 
to  injurious  influences,  may  pass  over  into  a  catarrhal  or  even  a 
blennorrhoeal  conjunctivitis.  Confinement  in  dusty,  smoky  rooms, 
or  in  those  filled  with  animal  exhalations,  is  likewise  a  frequent 
cause  of  conjunctivitis. 

Among  the  local  causes  which  induce  or  maintain  conjunctivitis 
are  strictures  of  the  nasal  duct,  diseases  of  the  margins  or  of  the 
glands  of  the  lids,  as,  for  instance,  distention  of  the  tarsal  glands 


256  SIMPLE    CONJUNCTIVITIS. 

by  retained  secretions,  distichiasis,  etc.  Straining  the  eyes  at 
work,  especially  by  insufficient  light,  tends  to  maintain  an  already 
existing  conjunctivitis. 

The  course  of  the  disease  varies  with  the  cause  exciting  it. 
Simple  cases  may  pass  away  in  a  few  days,  but  other  cases,  especi- 
ally where  the  exciting  causes  cannot  be  fully  removed^  may  be 
very  protracted. 

Chi'onic  conjunctivitis  generally  causes  relaxation  of  the  con- 
junctiva, with  hypersemia  either  of  the  larger  vessels  alone  or  of 
the  capillaries  also.  This  relaxation  becomes  more  noticeable 
when,  as  in  old  people,  the  skin  and  muscle  are  already  relaxed. 
In  such  cases  an  ectropion  or  sinking  of  the  lid  is  likely  to  occur. 

In  other  cases  there  develop  gradually  a  swelling  of  the  mucous 
membrane  and  a  gradual  transition  into  a  chronic  blennorrhoeal 
or  granular  process.  The  danger  of  consecutive  corneal  affections 
then  becomes  greater  than  is  the  case  in  simple  chronic  conjunc- 
tivitis. 

The  treatment  must,  of  course,  in  the  first  place,  be  directed 
toward  removing  all  hurtful  influences.  The  condition  of  the 
mucous  membrane  determines  what  further  remedies  are  to  be 
employed.  So  long  as  the  inflammation  is  still  progressive,  only 
antiphlogistic  and  derivative  treatment  is  indicated,  perhaps  simple 
applications  of  cold  water  or  a  dilute  solution  of  lead,  say  10 
drops  of  liquor  plumbi  acetatis  to  a  teacup  of  water.  So  soon  as  a 
relaxation  of  the  mucous  membrane  is  apparent,  astringent  eye- 
waters are  to  be  used,  say  a  ^  per  cent,  solution  of  sulphate  of  zinc 
or  neutral  acetate  of  lead  dropped  in  the  eye  three  times  daily,  or, 
where  there  is  greater  swelling  or  more  copious  muco-purulent 
secretion,  a  solution  of  nitrate  of  silver  also  ^  per  cent. 

If  the  patient  can  be  seen  daily,  a  cure  may  be  effected  sooner, 
by  pencilling  upon  the  conjunctiva  of  the  lids  a  2  to  4  per  cent, 
solution  of  sulphate  of  zinc,  or  1  to  3  per  cent,  acetate  of  lead, 
or  1  to  2  per  cent,  nitrate  of  silver.  In  all  cases  the  superfluous 
solution  remaining  after  the  application,  should  be  immediately 
washed  away  with  pure  Mater.  Cold-water  dressings  are  to  be 
made  afterward,  so  long  as  pain  remains  in  the  eye. 

If  the  conjunctivitis  be  complicated  by  a  diseased  condition  of 
the  tarsal  glands,  made  evident  by  a  redness  of  the  margins  of 
the  lids  and  an  accumulation  of  the  glandular  secretions  between 


ATROPINE    CONJUNCTIVITIS.  257 

the  roots  of  the  cilia,  eye-washes  are  often  not  well  borne,  or  at 
least  do  not  accomplish  the  desired  result.  In  such  cases  it  is 
well  to  try  a  salve  |^  to  1  per  cent,  red  or  white  precipitate  of  mer- 
cury, perhaps  with  the  addition  of  some  oxide  of  zinc  or  a  few 
drops  of  the  solution  of  acetate  of  lead,  causing  it  to  be  rubbed 
each  evening  along  the  margin  of  the  lids. 

Other  means  recommended  in  conjunctivitis,  especially  in  the 
chronic  or  oft-recurring  forms,  are  washes  of  corrosive  subli- 
mate (1  or  2  parts  in  a  thousand),  solutions  of  alum,  aluminate  of 
copper,  borax,  etc. 

Atropine  conjunctivitis,  which  sometimes  develops  after  the  long 
use  of  atropine,  deserves  a  special  mention.  It  occurs  sometimes 
in  the  form  of  a  simple  inflammatory  swelling  of  the  mucous 
membrane  with  a  muco-puriilent  secretion,  often,  too,  in  connection 
with  the  swelling  of  the  conjunctival  follicles,  or  there  may  be 
only  slight  swelling  but  great  hypersemia  and  a  copious  secretion 
of  tears.  In  connection  with  this  condition,  redness  and  exco- 
riation of  the  skin  of  the  lid  often  appear. 

Preparations  of  atropine,  which  irritate  and  immediately  cause 
pain  and  redness  after  being  dropped  in  the  eye,  ought  of  course 
not  to  be  used.  But  even  perfectly  neutral  sulphate  of  atropine 
has  the  above-named  unpleasant  property.  Individual  predispo- 
sition is  certainly  one  of  the  elements  involved,  since  only  a  few 
of  the  patients  treated  with  atropine  are  affected  with  this  kind  of 
conjunctivitis. 

The  muco-purulent  secretion  of  this  conjunctivitis  is  of  course 
as  infectious  as  all  other  secretions  of  this  kind.  It  is  well,  there- 
fore, especially  in  clinical  practice,  never  to  drop  atropine  in  the 
eyes  with  a  camel-hair  pencil,  but  always  with  a  small  glass  pipette, 
— a  thin  glass  tube,  its  lower  end  somewhat  narrowed  and  its 
upper  end  provided  with  a  short  piece  of  rubber  tube  closed  at 
the  top.  In  the  clinic,  each  patient  requiring  atropine  treatment 
should  be  provided  with  his  individual  pipette.  In  this  way  the 
danger  of  spreading  the  disease  by  contagion  is  diminished.  The 
only  way  to  render  the  occurrence  of  this  complication  less  frequent 
is  to  use  as  little  atropine  as  possible  in  all  cases  where  its  appli- 
cation must  be  continued  a  long  time. 

The  treatment  is  the  same  as  in  other  forms  of  conjunctivitis; 
beginning  with  cold-  or  lead-water  dressings,  following  later  with 


258  BLENNORRHCEAL   CONJUNCTIVITIS. 

astringents,  or  pencilling  with  a  1  or  2  per  cent,  solution  of  nitrate 
of  silver.  My  experience  has  not  confirmed  the  oft-repeated  as- 
sertion that  preparations  of  lead  have  a  specific  action  in  the  cure 
of  atropine  conjunctivitis. 

If  possible,  it  is  well  to  dispense  with  the  use  of  atro])ine ;  if 
mydriasis  must  be  maintained,  a  solution  of  extract  of  belladonna 
may  be  substituted  for  the  sulphate  of  atropine,  and  the  conjunc- 
tivitis treated  at  the  same  time.  After  the  conjunctivitis  has  been 
fully  cured,  the  use  of  atropine  ought  not  to  be  begun  again,  since 
a  few  drops  are  sufficient  to  cause  a  relapse. 

Distinct  from  this  atropine  conjunctivitis,  is  a  very  rare  atropine 
idiosyncrasy  of  the  conjunctiva.  Cases  occasionally  occur  in  which 
immediately  after  instilling  atropine,  pains  ensue,  and  following 
quickly  on  these  are  acute  erysipelatous  inflammation  of  the  con- 
junct! v^a  and  great  swelling  both  of  it  and  of  the  eyelids.  In 
milder  forms  of  this  idiosyncrasy  the  atropine  causes  only  a 
feeling  of  burning  and  pricking,  with  redness  of  the  eyes  and  a 
copious  secretion  of  tears.  Many  such  patients  bear  extract  of 
belladonna  very  well. 

BLENNORRHCEAL,    CONJUNCTIVITIS. 

Acute  blennorrhoea  develops  in  an  eye  previously  healthy  or  one 
already  suffering  from  some  conjunctival  disease,  with  the  symp- 
toms of  a  rapid  inflammation  of  the  conjunctiva.  The  whole 
surface  of  the  mucous  membrane  is  reddened  by  an  excessive  hy- 
persemia,  and  often,  especially  upon  the  sclera,  is  infiltrated  with 
hemorrhages.  The  looser  the  subconjunctival  tissue  the  greater 
the  swelling.  It  is  therefore  least  near  the  margin  of  the  lid, 
on  account  of  the  close  connection  of  the  conjunctiva  with  the 
tarsus  at  this  point;  the  swelling  increases  toward  the  fornix, 
and  finally  attains  such  a  volume  that  when  the  lids  are  everted 
and  the  patient  is  told  to  look  downward,  or  upward,  it  puffs 
forward  like  a  broad,  ring-shaped  cushion.  The  surface  of  the 
mucous  membrane  is  generally  smooth,  glistening,  tense,  and 
bright  red ;  in  severe  cases  it  may  present  a  grayish  appear- 
ance which,  by  touching  lightly  with  a  brush,  will  be  seen  to 
be  caused  by  an  exudate  not  upon  but  in  the  mucous  membrane 
itself. 

The  scleral  conjunctiva  is  likewise  very  red  and  infiltrated  with 


BLENNORRHCEAL   CONJUNCTIVITIS.  259 

an  inflammatory  exudate.  In  mild  cases  this  exudate  is  of  a 
serous  character,  of  a  yellow  or  reddish  color ;  in  more  severe 
cases  it  assumes  a  dense,  so-called  fleshy  character,  so  that  the 
greatly  swollen  conjunctiva  surrounds  the  cornea  like  a  wall. 
Under  these  circumstances  the  cornea  generally  appears  small, 
because  the  limbus  conjunctivai  corneae  participates  in  the  vas- 
cularization and  swelling,  and  the  thickened  conjunctiva  sclerse 
presses  over  the  edge  of  the  cornea  on  every  side.  The  swelling 
of  the  conjunctiva  is  generally  called  "  chemosis"  or  "  chemotic 
swelling." 

The  eyelids,  too,  particularly  near  their  margins,  or  perhaps 
throughout  their  whole  extent,  are  of  a  bright  or  livid  red,  in  con- 
sequence of  excessive  hyperaemia.  The  upper  lid,  owing  to  its 
increased  volume,  hangs  heavily  downward,  and  can  be  only  par- 
tially raised  by  the  action  of  the  levator.  In  very  acute  cases 
the  infiltration  extends  downward  upon  the  cheek  and  upward 
above  the  eyebrows.  A  decided  increase  in  the  temperature  of 
the  lids  is  perceptible. 

The  secretion  is  at  first  thin,  serous,  of  a  yellowish  tinge,  due 
to  blood  coloring  matter,  and  is  mixed  with  gray  flakes.  Since 
the  puncta  lacrymalia  are  forced  away  from  the  eyeball  by  the 
swelling  of  the  lids,  the  secretion  runs  continually  over  their  mar- 
gins and  causes  excoriation  of  the  cheek.  Often,  especially  at 
first,  the  secretion  is  so  coagulable  that  one  finds  upon  the  surface 
of  the  everted  lids  a  membranous  coagulated  layer  of  exudation, 
which  can  generally  be  easily  removed,  and  sometimes  but  not 
always  leaves  a  slightly  bleeding  mucous  surface.  This  so-called 
croupous  form  possesses  no  prognostic  importance.  After  a  few 
days  the  secretion  becomes  decidedly  purulent,  of  a  creamy  con- 
sistency, yellowish  and  often  greenish,  and  more  or  less  profuse  in 
quantity. 

In  the  course  of  a  few  days  the  mucous  membrane  assumes  a 
somewhat  dilFerent  api)earance.  It  no  longer  appears  smooth  and 
glistening,  but  more  velvety;  its  folds  become  more  relaxed,  more 
numerous  and  smaller,  and  are  traversed  by  cross-folds,  so  that 
the  surface  of  the  mucous  membrane  appears  more  and  more  un- 
even. Simultaneously,  a  hypertrophy  begins  in  the  tissue  of  the 
mucous  membrane  itself,  which  furnishes  to  these  irregularities  of 
the  surface  a  more  solid  substratum. 


260  BLENNOREHCEAL   CONJUNCTIVITIS. 

The  great  danger  in  these  severe  cases  of  blennorrhoea  is  that 
the  cornea  will  participate  in  the  process.  During  the  first  few 
days,  while  the  conjunctival  swelling  is  still  increasing,  the  cornea 
generally  remains  intact;  but,  unfortunately,  it  is  not  safe  to  base 
a  favorable  prognosis  upon  the  fact  that  the  cornea  remains  free 
during  the  progressive  stage  of  the  disease;  that  cannot  be  done 
till  the  disease  has  passed  its  acme  and  has  entered  upon  an  evi- 
dently regressive  stadium.  The  period  of  the  disease  in  which  the 
cornea  is  most  endangered  is  that  at  which  the  conjunctival  swell- 
ing has  attained  its  maximum,  and  the  danger  is  the  more  threat- 
ening the  more  the  conjunctiva  sclerae  is  involved  in  the  process, 
and  particularly  where  chemotic  swelling  is  protracted  into  the 
later  stages  of  the  disease.  The  following  are  the  most  usual 
forms  of  corneal  affections : 

Among  the  most  dangerous  of  the  blennorrhoea!  affections  of 
the  cornea  is  the  annular  marginal  ulcer.  It  may  occur  in  the 
form  of  a  narrow  furrow  close  to  and  parallel  with  the  margin  of 
the  cornea.  At  first  it  seems  an  unimportant  loss  of  substance, 
hardly  wider  than  a  hair,  with  a  smooth  and  glistening  floor,  but 
it  creeps  gradually  farther  around  the  margin  of  the  cornea,  and 
at  the  same  time  becomes  broader  and  deeper. 

In  other  cases  there  develops  at  some  one  point  upon  the  margin 
of  the  cornea,  generally  upon  its  upper  part,  a  purulent  infiltration, 
which  spreads  rapidly  in  a  direction  parallel  to  the  margin  of  the 
cornea. 

At  first  the  centre  of  the  cornea  seems  relatively  little  changed. 
So  soon,  however,  as  the  ulcer  spreads  more  than  half-way  around 
the  cornea,  there  ensue  a  deep-gray  color  and  necrotic  destruction 
of  the  central  part  of  the  cornea. 

In  other  cases  the  cornea  appears  misty.  Necrotic  softening 
takes  place;  one  layer  after  another  of  the  corneal  substance  is 
cast  off  in  quick  succession.  This  process  may  run  a  somewhat 
more  favorable  course  when  it  affects  only  a  small  portion  of  the 
cornea,  and  perforation  occurs  quickly. 

A  very  frequent  form  of  blennorrhoeal  corneal  affection  is  the 
circumscribed  purulent  infiltration.  Its  prognosis  depends  upon 
the  course  of  the  blennorrhoea.  If  it  occur  very  early  in  the  first 
stages  of  an  acute  blennorrhoea,  it  inclines  to  increase  rapidly, 
both  in  depth  and  in  surface,  quickly  causing  perforation  and  de- 


BLENNOREHCEA   NEONATORUM.  261 

struction  of  the  cornea.  Wliere  the  course  of  the  blennorrhoea  is 
less  acute,  there  is  more  chance  that  the  process  will  be  arrested  and 
healing  occur  before  the  entire  cornea  is  destroyed.  Frequently 
there  are  in  the  cornea  at  the  same  time  several  such  points  of 
purulent  infiltration,  in  which  case  the  danger  to  the  cornea  is,  of 
course,  increased. 

The  suppurative  process  which  occurs  in  the  cornea  during  the 
course  of  an  acute  conjunctival  blennorrhoea  has  this  peculiarity, 
that  the  pus  never  sinks  downward  in  the  substance  of  the  cornea, 
nor  is  hypopion  ever  formed.  But,  as  in  other  suppurations  of 
the  cornea,  iritis  is  a  frequent  complication. 

In  blennorrhoeal  conjunctivitis  of  the  milder  forms,  small,  cir- 
cumscribed corneal  infiltrations  are  most  apt  to  occur,  with  per- 
haps extensive  loss  of  epithelium  and  diffuse  clouding  of  the  cor- 
neal tissue  thus  exposed,  and  shallow  ulcers  with  smooth,  reflecting 
floors. 

Blennorrhoea  may  occur  idiopathically,  or  in  consequence  of 
some  external  hurtful  cause,  especially  in  cases  where  the  conjunc- 
tiva was  previously  quite  normal.  But  very  severe  cases  not 
infrequently  occur  for  which  no  cause  can  be  with  certainty  deter- 
mined. In  the  great  majority  of  cases,  however,  the  disease  is 
acquired  by  infection  with  the  purulent  blennorrhoeal  secretion. 
The  most  frequent  source  is  the  blennorrhoeal  disease  of  the  con- 
junctiva itself. 

Among;  the  inoculated  forms,  the  first  to  be  mentioned  is  the 
blennorrhoea  neonatorum.  The  circumstance  that  this  affection 
occurs  always  within  a  few  days,  generally  three  or  four,  after 
birth,  points  very  decidedly  to  an  infection  occurring  either  at  that 
time  or  very  soon  after  it.  It  is,  however,  by  no  means  necessary 
that  the  mother  should  have  had  a  virulent  vaginal  blennorrhoea. 
It  is  probable  that  any  muco-purulent  secretion  which  during 
delivery  accidentally  gets  into  the  conjunctival  sac,  is  sufficient 
to  produce  this  condition.  It  is  possible  that  some  days  later, 
through  carelessness,  an  infection  may  be  caused  by  the  lochial 
discharges.  Frequently  only  one  eye  is  at  first  affected;  still,  it  is 
seldom  possible  to  protect  the  second  from  infection  by  the  first. 
The  intensity  with  which  blennorrhoea  neonatorum  occurs,  varies 
greatly,  probably  on  account  of  differences  in  the  infecting  secre- 
tion.    Accordingly,  the  symptoms  presented  by  the  swelling  of  the 


262       .     GONOERHCEAL  BLENNORRHCEA. 

conjunctiva  and  the  purulent  secretion  are  sometimes  more  and 
sometimes  less  threatening.  Frequently  the  exudation  from  the 
mucous  membrane  is  so  copious  that,  upon  everting  the  lids,  one 
can  see  it  collect  upon  the  surfaces  while  under  observation. 
Frequently  the  exudate  is  at  the  same  time  so  coagulable  that  it 
immediately  forms  a  membrane  which  covers  the  mucous  surface, 
and,  when  the  lids  are  closed,  may  extend  unbroken  from  the 
inner  surface  of  one  to  the  other.  Frequently  the  mucous  mem- 
brane shows  also  a  great  inclination  to  bleed,  so  that  the  eversion 
of  the  lids  or  the  least  touch  suffices  to  provoke  a  hemorrhage, 
which,  however,  when  the  lids  are  returned  to  their  normal  posi- 
tion, generally  ceases  again  spontaneously.  This  symptom  has  no 
special  prognostic  or  therapeutic  importance. 

During  the  first  days  of  a  severe  blennorrhoea  neonatorum' the 
cornea  often  shows  a  slight  diffuse  cloudiness  throughout  its 
whole  extent;  this,  however,  disappears  entirely  under  suitable 
treatment.  Any  corneal  affection  which  occurs  is  generally  in 
the  form  of  a  circumscribed  purulent  infiltration. 

Gonorrhoeal  blennorrhoea  is  caused  by  inoculation  of  the  gonor- 
rhoeal  secretion  upon  the  conjunctiva,  and  often  proves  one  of  the 
severest  and  most  dangerous  forms.  The  inflammation  may,  how- 
ever, assume  a  milder  type  in  cases  where  the  inoculating  secretion 
has  been  diluted. 

There  are  no  special  symptoms  by  which  a  gonorrhoeal  blennor- 
rhoea can  be  recognized  as  such  in  cases  where  it  is  not  possible 
to  discover  the  gonorrhoea  as  a  cause.  Moreover,  this  etiological 
fact  has  no  influence  upon  the  prognosis  or  treatment  of  the 
blennorrhoea. 

Blennorrhoeas  in  which  the  infection  is  caused  by  inoculation 
with  conjunctival  secretions  are  very  frequent,  since  all  conjunc- 
tival affections  accompanied  by  a  muco-j)urulent  secretion  may  be 
regarded  as  infectious.  As  a  general  thing,  there  is  a  certain 
agreement  in  type  between  the  original  and  the  inoculated  disease. 
But  one  often  sees  very  malignant  blennorrhoeas  resulting  by 
inoculation  from  slight  conjunctival  affections. 

The  course  and  prognosis  of  acute  conjunctival  blennorrhoeas 
depend  in  the  first  place  upon  the  degree  of  the  inflammation. 
Mild  cases  may  be  cured  by  proper  treatment  in  from  one  to  two 
weeks;  severe  ones  in  from  six  to  eight  weeks.     The  most  impor- 


BLENNORRHCEAL    CONJUNCTIVITIS.  263 

tant  point  is  the  behavior  of  the  cornea.  The  clanger  to  that  is 
in  direct  relation  to  the  participation  in  the  process  on  the  part  of 
the  conjunctiva  sclera?.  The  greater  the  chemotic  swellings  and 
the  longer  it  continues,  the  greater  the  danger  to  the  cornea. 

Even  in  the  severest  forms  of  blennorrhoea,  pathological  corneal 
processes  do  not  generally  appear  at  the  very  first,  but  upon  the 
third  or  fourth  day  of  the  affection,  after  it  has  reached  or 
already  passed  its  highest  point.  As  a  general  rule,  the  later  in 
the  course  of  a  blennorrhoea  a  corneal  affection  ap])ears,  the  more 
amenable  is  it  to  treatment. 

The  treatment  in  a  case  of  unilateral  blennorrhoea  must,  in  the 
first  place,  be  directed  toward  preventing  an  infection  of  the  second 
eye.  This  is  most  surely  done  by  a  properly  applied  protective 
bandage.  The  healthy  eye  is  covered  by  a  pad  of  charpie  and 
covered  with  linen  made  impermeable  by  collodion. 

The  treatment  of  the  eye  attacked  with  blennorrhcea  must  at 
first  be  antiphlogistic.  The  most  important  means  to  be  employed 
during  the  first  days  are  cold-water  dressings,  whose  temperature 
is  to  be  regulated  by  that  of  the  eyelids.  Where  the  temperature 
is  very  high  it  is  best  to  lay  the  compresses  on  ice,  and  from  that 
directly  upon  the  eye.  For  a  lower  degree  of  temperature  it 
suffices  to  use  ice-water  for  wetting  the  compresses.  In  every 
case  the  dressing  must  be  changed  very  frequently,  say  every  two 
or  three  minutes,  so  that  they  may  not  become  warm.  So  soon 
as  the  swelling  of  the  lids  begins  to  diminish,  or,  in  mild  cases,  at 
the  very  beginning,  it  is  well  to  add  to  the  water  used,  a  few 
drops  of  the  solution  of  acetate  of  lead.  Frequently  the  appli- 
cation of  cold  diminishes  greatly  the  pain  and  burning  in  the 
eyelids.  Simultaneously  the  lids  must  be  occasionally  carefully 
separated  and  the  secretion  removed  by  washing  out  the  conjunc- 
tival sac  with  a  soft  camel-hair  pencil. 

If,  in  spite  of  this,  severe  pain  continue,  a  few  drops  of  sul- 
phate of  atropine  in  a  1  per  cent,  solution  often  do  good  service. 
Leeches,  placed  on  the  temple  about  midway  between  the  outer 
canthus  and  the  ear,  exert  often  an  inexplicable  influence  in  allay- 
ing the  pain.  If  during  the  first  days  of  the  disease  the  conjunc- 
tiva sclerse  be  infiltrated  by  a  bloody  serous  exudation,  escape 
may  be  given  it  by  a  few  incisions  with  the  points  of  the  scissors. 
Scarification  is  not  so  efficacious  in  the  flesh-like  chemotic  swelling 


264  BLENNOREHCEAL    CONJUNCTIVITIS. 

which  occurs  later,  in  which  the  exudation  has  more  consistency. 
Excision  of  any  portions  of  the  mucous  membrane  is  to  be  abso- 
lutely avoided. 

The  local  treatment  of  the  conjunctiva  is  first  indicated  when 
the  disease  has  evidently  passed  into  a  regressive  stadium.  If  the 
lids  were  greatly  swollen  and  their  skin  very  red  and  glistening, 
they  now  begin  to  grow  paler,  and  fine  wrinkles  appear.  The 
mucous  membrane,  too,  no  longer  seems  so  tense  and  glistening, 
but  is  more  relaxed,  and  is  traversed  by  several  folds  parallel 
to  the  edtre  of  the  lid.  The  nature  of  the  secretion  is  also  to  be 
noticed.  So  long  as  it  is  still  serous,  with  only  an  occasional 
flake  of  pus,  caustics  must  be  used  very  carefully ;  but  when  the 
secretion  becomes  decidedly  purulent  they  may  be  used  more 
boldly. 

In  general  it  is  advisable  not  to  be  too  hasty  in  beginning  the 
use  of  caustics.  If  in  a  recent  case  of  blennorrhoea  one  is  doubtful 
whether  the  use  of  caustics  is  yet  indicated,  it  is  better  to  wait 
than  to  cauterize  too  early,  since  a  premature  use  of  caustics  may 
be  followed  by  the  most  serious  consequences.  For  instance,  by 
such  mistaken  treatment  what  would  have  been  a  mild  process 
may  be  excited  to  an  inflammatory  condition,  which  it  would 
never  have  reached  under  a  simple  antiphlogistic  treatment;  and 
just  these  inflammatory  conditions  which  have  been  induced  by 
too  early  cauterization  show  a  great  inclination  to  associate  them- 
selves with  destructive  corneal  processes.  The  rule  is  difl'erent  in 
old  neglected  cases.  Here  the  last  possibility  of  salvation  may  be 
lost  by  postponing  the  cauterization,  which  when  properly  con- 
ducted is  the  surest  means  by  which  to  check  the  blennorrhoeal 
process. 

Generally  it  is  advisable  to  use,  for  the  first  cauterization,  a 
dilute  solution  of  nitrate  of  silver,  say  from  J  to  2  per  cent.,  and, 
if  that  be  well  borne,  to  proceed  gradually  to  the  use  of  stronger 
solutions,  say  2  to  3  per  cent.  The  use  of  the  mitigated  pencil 
of  nitrate  of  silver  (nitrate  of  silver  with  nitrate  of  potassium)  is 
not  near  so  well,  for  when  long  continued  it  is  very  apt  to  cause  a 
superficial  cicatrization  of  the  mucous  membrane. 

In  order  to  cauterize  the  lids,  each  is  everted  separately,  as  in 
this  way  the  fornix  conjunctivae,  the  part  most  imjjortant  to  be 
reached,  is  best  exposed.     In  using  the  solution  of  nitrate  of  silver, 


BLENNORRHCEAL   CONJUNCTIVITIS.  265 

its  action  upon  the  conjunctiva  may  be  regulated  by  allowing 
it  to  remain  a  greater  or  less  time  before  washing  it  awav  with 
water. 

In  the  treatment  by  caustics,  it  is  always  to  be  remembered  that 
under  no  circumstances  should  any  destruction  of  the  tissue  of  the 
raucous  membrane  be  caused.  Only  its  epithelial  layer  should 
be  couverted  into  a  thin  eschar,  and  the  cauterization  ought  never 
to  be  repeated  until  this  eschar  has  been  cast  off  and  the  epithelial 
layer  regenerated.  If  the  applications  have  been  properly  made, 
the  average  time  required  for  this  is  about  24  hours.  The  cauteri- 
zation should  therefore  be  repeated  daily  at  the  same  hour.  If  one 
finds  any  remains  of  the  eschar,  it  shows  that  the  last  cauterization 
was  too  strong  for  the  condition  of  the  mucous  membrane,  and  it 
is  then  well  to  postpone  a  new  application,  or  else  carefully  limit 
it  to  those  portions  of  the  surface  where  the  epithelium  has  been 
renewed. 

The  curative  effect  of  the  cauterization  is  first  manifested  by  a 
decrease  of  the  purulent  secretion.  It  is  only  very  seldom  that  a 
profuse  purulent  secretion  obstinately  persists  in  spite  of  a  sys- 
tematic cauterization.  In  these  exceptional  cases  the  applications 
must  be  made  stronger  or  repeated  oftener,  perhaps  twice  in  24 
hours.     Generally  the  latter  course  is  preferable. 

After  each  cauterization  cold-water  dressings  should  be  applied, 
to  soothe  the  pain  and  prevent  too  great  a  reaction. 

When  during  this  treatment  the  purulent  secretion  and  the 
swelling  of  the  raucous  membrane  diminish,  it  is  well  to  pass 
gradually  to  the  use  of  weaker  solutions. 

The  above  rules  are  not  altered  by  the  appearance  of  patho- 
logical processes  in  the  cornea.  If  the  cauterization  be  indicated 
by  the  condition  of  the  mucous  membrane,  its  effect  can  be  only 
favorable  upon  the  co-existing  corneal  affection. 

On  the  other  hand,  corneal  affections  which  occur  early  in  the 
course  of  a  severe  blennorrhoea,  in  general  furnish  ground  for  an 
unfavorable  prognosis,  and  are  not  likely  to  be  improved  by  early 
cauterization.  In  all  these  corneal  affections  the  use  of  sulphate 
of  atropine  in  at  least  a  1  per  cent,  solution  is  specially  indicated. 
It  must  be  dropped  into  the  eye  as  often  as  is  necessary  to  induce 
and  maintain  mydriasis. 

The  early  use  of  atropine  tends  also  to  prevent  the  occurrence 

18 


266  BLEXNORRHCEAL   COXJITNCTIVITIS. 

of  iritis,  which  is  so  apt  to  be  a  complication  of  these  corneal 
affections. 

If  the  corneal  ulcer  penetrate  so  deeply  that  its  floor  is  evi- 
dently forced  outward  by  the  intraocular  pressure,  it  is  often  "vvell 
to  puncture  it,  and  where  possible  to  establish  for  some  time  a  fis- 
tulous opening  into  the  anterior  chamber.  In  this  way  there  is 
the  greatest  chance  of  limiting  the  ulceration  and  retaining  that 
part  of  the  cornea  still  intact. 

If  after  spontaneous  or  artificial  perforation  of  the  cornea,  a 
prolapse  of  the  iris  occur,  it  may  be  left  to  itself  so  long  as  it 
remains  small,  but  if  an  increase  and  expansion  of  the  prolapse 
occur,  it  should  be  removed  with  the  scissors. 

Chronic  blennorrhoeal  processes  for  the  most  part  remain  after 
an  acute  inflammation  of  the  conjunctiva.  They  often  follow  in- 
flammations which  were  originally  slight  and  perhaps  for  that  very 
reason  were  neglected.  Other  influences  often  play  an  important 
role,  for  instance,  unhealthy  dwellings,  and  the  continual  action  of 
irritating  substances. 

The  condition  of  the  mucous  membrane  is  nearly  the  same  as 
in  the  later  stages  of  the  acute  blennorrhoeal  inflammation.  The 
conjunctiva  is  reddened,  swollen,  wrinkled,  and  discharges  a  more 
or  less  copious  muco-puruleut  secretion.  Frequently,  however, 
there  are  still  other  changes.  The  surface  of  the  mucous  mem- 
brane presents  a  greater  or  less  number  of  slight  round  promi- 
nences, due  partly  to  swelling  of  the  conjunctival  lymph  follicles, 
and  partly,  when  the  process  has  been  very  protracted  and  subject 
to  frequent  exacerbations,  to  proliferations  in  the  mucous  membrane 
itself. 

The  mucous  membrane  is  often  so  tender  that  it  bleeds  when 
the  lids  are  everted  or  lightly  touched.  Probably  it  is  at  places, 
especially  in  the  tarsal  part,  actually  raw,  which  gives  rise  to  the 
development  of  excrescences  closely  resembling  the  granulations 
which  form  on  a  wound.  The  surface  of  the  conjunctiva  is  in 
such  cases  uneven,  studded  with  round  or  cockscomb-like  promi- 
nences^ projecting  above  the  general  level  of  the  conjunctiva, 
especially  on  the  tarsal  part  of  the  upper  lid. 

Now,  since  it  is  usual  to  call  all  irregularities  upon  the  conjunc- 
tiva "granulations,"  these  cases  are  called  "granular  conjunc- 
tivitis."    Other  cases  of  the  same  kind  may,  on  account  of  the 


BLENNORRHCEAL   CONJUNCTIVITIS.  267 

decided  roughness  of  the  surface  of  the  mucous  membrane,  be  as 
properly  called  "  trachoma"  as  "  chronic  blennorrhoea." 

Chronic  blennorrhoeal  conjunctivitis  is  frequently  associated  with 
corneal  affections.  Sometimes  there  is  a  superficial  loss  of  sub- 
stance with  a  transparent  floor ;  sometimes  extensive  superficial 
exfoliation  with  diffuse  clouding  of  the  exposed  and  neighboring 
corneal  tissue;  sometimes  saiall,  circumscribed  infiltrations,  which 
at  first  produce  great  irritation,  and,  notwithstanding  their  small- 
ness,  frequently  cause  perforation  of  the  cornea.  After  existing 
some  time,  these  infiltrations  usually  become  vascularized  from  the 
margin  of  the  cornea. 

In  the  course  of  the  disease  many  acute  exacerbations  occur, 
which  may  proceed  as  well  from  the  cornea  as  from  the  conjunc- 
tiva; they  assume,  therefore,  more  or  less  the  character  of  a 
decided  acute  blennorrhoea.  In  any  such  case  the  cornea  is  ex- 
posed to  new  danger. 

The  treatment  must,  in  the  first  place,  be  directed  toward  im- 
proving the  hygienic  surroundings  of  the  patient  and  removing 
all  hurtful  influences.  In  other  respects  it  scarcely  varies  from 
that  of  acute  blennorrhoea.  The  cauterizations  must  be  begun 
very  carefully,  since  the  mucous  membrane  does  not  bear  them  well 
in  all  cases.  If  a  weak  solution  of  nitrate  of  silver  cause  only 
an  increase  of  the  irritability,  a  1  or  2  per  cent,  solution  of  acetate 
of  lead,  sulphate  of  zinc,  or  tannic  acid  should  be  tried.  Generally, 
however,  a  2  or  3  per  cent,  solution  of  nitrate  of  silver  is  well 
borne,  and  reduces  gradually  the  swelling  of  the  mucous  mem- 
brane. 

Even  considerable  excrescences  of  the  mucous  membrane  gen- 
erally shrink  up  under  this  treatment  in  the  course  of  a  few  weeks; 
this  being  so,  the  experiment  of  cutting  ofl"  the  cockscomb  growths 
to  the  level  of  the  mucous  membrane  should  be  avoided.  This 
proceeding  is  superfluous  and  injurious,  for  it  causes  an  unnecessary 
loss  of  substance.  Nevertheless,  in  many  of  these  cases  healing 
occurs  with  formation  of  cicatricial  tissue,  which  gives  the  mucous 
membrane  a  marmorated  appearance. 

If  acute  exacerbations  occur,  the  cauterizations  should  be 
stopped  and  antiphlogistic  treatment  substituted.  The  complica- 
tion of  keratitis,  which  usually  is  present,  gives  the  indication  for 
the  use  of  atropine. 


268  DIPHTHERITIC   CONJUNCTIVITIS. 


DIPHTHERITIC  CONJUNCTIVITIS. 

BIphtheritic  conjunctivitis  is  characterized  by  the  same  changes 
as  (iiphtheritis  on  any  other  mucous  membrane.  A  coagulable 
exudate  is  deposited  within  the  tissue  of  the  mucous  membrane 
itself.  The  diphtheritic  infiltration  may  aifect  the  conjunctiva 
only  at  certain  places,  and  then  it  is  mostly  on  the  tarsal  part  of 
the  upper  lid,  or  it  may  involve  the  entire  membrane. 

Often  there  is  simultaneously  a  more  or  less  adherent  coagulated 
membrane  upon  the' mucous  surface,  without  its  presence  or  ab- 
sence, however,  being  of  any  particular  diagnostic  importance. 

Diphtheritic  conjunctivitis  generally  occurs  at  the  very  first  in 
the  form  of  a  severe  inflammation  ;  the  lids  are  greatly  swollen, 
are  of  a  bright  or  livid  red,  hard  and  hot  to  the  touch.  The 
higher  the  temperature,  the  greater  the  swelling,  and  the  harder 
the  lids,  the  more  difficult  is  it  generally  to  evert  them  or  to  open 
the  eyes,  and  the  more  extensive  is  the  diphtheritic  infiltration. 

In  partial  diphtheritis,  in  which  the  infiltration  and  the  symp- 
toms depending  on  it  have  not  attained  their  full  development, 
there  is  generally  less  difficulty  in  everting  the  lids. 

Tlie  tarsal  part  of  the  upper  lid  is  then  found  to  be  of  a  bright 
yellowish -gray  color,  due  to  an  exudation  not  on,  but  in,  the 
mucous  membrane.  The  spot  occupied  by  the  diphtheritic  ex- 
udate appears  generally  somewhat  depressed,  as  the  rigidity  of  the 
exudate  prevents  the  swelling  of  the  conjunctiva,  which  is  very 
great  at  other  places,  and  is  accompanied  by  such  hypenemia  that 
ecchymoses  are  often  visible  within  the  tissues,  especially  upon  the 
sclera.  Hemorrhages  from  the  conjunctiva  palpebrarum  may  be 
caused  by  simply  everting  the  lids.  In  some  cases  superficial 
ulcerations  of  the  diphtheritic  mucous  membrane  may  be  the 
source  of  such  hemorrhages.  Frequently  the  diphtheritis  of  the 
tarsal  part  extends  to  the  intermarginal  part  of  the  lids,  and  in 
many  cases  there  occur  excoriations  on  the  outer  skin  which 
assume  the  character  of  diphtheritic  ulcers.  This  is  especially  the 
case  with  the  under  lid,  over  which  the  swollen  upper  lid  hangs, 
thus  placing  the  skin  in  immediate  contact  with  the  diphtheritic 
secretions. 

Diphtheritic  excoriations  occur  also  not  unfrequently  in  the 
nasal  cavities,  perhaps  by  the  direct  action  of   the  conjunctival 


DIPHTHERITIC   CONJUNCTIVITIS.  269' 

secretions  which  pass  through  the  lachrymal  duct.     In  rare  cases 
it  goes  on  to  diphtheritis  faucium  with  fatal  result. 

The  diphtheritic  process  may  be  limited  to  the  tarsal  part  of 
the  lid,  or,  without  passing  over  into  total  diphtheritis,  it  may 
extend  somewhat  upon  the  fornix  and  conjunctiva  sclerse.  The 
danger  to  the  cornea  is  thereby  greatly  increased.  Even  where 
there  are  small,  circumscribed  diphtheritic  spots  upon  the  con- 
junctiva sclerse  the  cornea  almost  always  participates  in  the  pro- 
cess, the  result  even  in  the  most  favorable  cases  being  a  partial 
ulceration. 

Total  diphtheritis  of  the  conjunctiva  occurs  generally  with  very 
severe  symptoms.  The  lids  are  greatly  swollen,  glistening,  livid 
red,  hard,  burning  hot  to  the  touch,  and  very  painful  when 
everted.  The  diphtheritic  infiltration  extends  through  the  entire 
mucous  membrane,  and  generally  the  cornea  is  destroyed  during 
the  first  few  days.  Either  it  becomes  clouded  throughout  its 
entire  extent  and  sloughs  away,  or  without  any  noticeable  cloud- 
ing one  layer  of  tissue  after  another  is  thrown  off. 

The  secretion  is  often  mixed  with  blood  or  with  flaky,  ragged 
clots. 

This  first  stage,  that  of  the  diphtheritic  infiltration,  lasts  from 
8  to  10  days,  after  which  the  resorption  of  the  diphtheritic  exudate 
begins.  Small  spots  begin  to  diminish  from  their  peripheries; 
wide-spread  infiltrations  begin  to  show  island-like  surfaces  of  be- 
ginning resolution.  In  these  last-named  spots  the  tissues  become 
more  expansible,  and  therefore  swell  above  the  surface  of  the 
adjoining  mucous  membrane,  which  is  still  infiltrated  with  the 
diphtheritic  exudate.  In  this  way  occur  the  diphtheritic  nodules 
(Knopfe)  described  by  Von  Graefe.* 

Upon  the  resorption  of  the  diphtheritic  infiltration  the  disease, 
especially  the  partial  forms,  may  go  on  to  absolute  recovery. 
Generally,  however,  after  severe  attacks  the  mucous  membrane 
does  not  return  immediately  to  its  normal  condition,  but  remains 
in  a  condition  of  relaxation,  swelling,  and  purulent  secretion. 
These  last  two  symptoms  may  be  quite  prominent.  When  the 
disease  assumed  this  form  Von  Graefe  described  it  as  in  the 
blennorrhoeal  stage. 

*  Arch.  f.  Opth.,  B.  i.  pag.  180. 


270  DIPHTHERITIC   CONJUNCTIVITIS. 

During  this  stage  the  danger  to  the  cornea  has  not  yet  passed. 
The  occurrence  of  cireumscrihed  purulent  infiltrations,  marginal 
ulcers,  etc.,  may  still  greatly  endanger  it. 

In  very  unfortunate  cases  there  follows  upon  this  second  stage 
still  a  third,  namely,  that  of  shrinking.  The  mucous  membrane 
appears  thin,  abnormally  smooth,  and  shortened  in  its  whole 
extent.  Tlie  tarsal  cartilages  are  bent  and  shrunken ;  there  is 
trichiasis  and  entropion  ;  in  short,  exactly  the  same  appearances 
most  frequently  presented  as  the  result  of  trachoma.  Probably  in 
these  cases  the  diphtheritic  infiltration  had  extended  into  the 
cartilages  and  there  caused  such  changes  as  finally  led  to  their 
atrophy  and  shrinkage. 

The  prognosis  depends  most  upon  whether  the  diphtheritis  is 
partial  or  total.  Total  diphtheritis  always  involves  the  greatest 
danger  to  vision.  In  partial  diphtheritis,  limited  to  the  tarsal 
part,  the  prognosis  is  no  more  unfavorable  than  in  blennorrhoea. 
The  more  the  diphtheritis  extends  upon  the  conjunctiva  of  the 
sclera  the  greater  the  danger  to  the  cornea.  If  the  disease  has 
passed  into  the  second  stage  and  the  cornea  has  not  been  affected, 
or  only  slightly  so,  it  may  generally  be  hoped  that  sight  will  be 
saved. 

Diphtheritic  conjunctivitis  occurs  both  epidemically  and  spo- 
radically. Infants  are  seldom  attacked.  The  greatest  number  of 
cases  are  between  the  ages  of  2  and  3  years.  Poorly  nourished 
children,  who  suffer  from  facial  eczema,  appear  to  be  specially 
predisposed.  After  the  third  year  the  predisposition  becomes  less, 
decreasing  gradually  as  time  goes  on. 

There  is  no  doubt  that  the  disease  is  contagious.  It  is  probable 
that  a  direct  inoculation  of  the  infectious  secretion  into  the  con- 
junctiva is  not  absolutely  a  condition  for  the  spread  of  the  disease. 
If  such  an  inoculation  occur,  a  diphtheritis  is  not  always  the  con- 
sequence, just  as  infection  with  blennorrhoeal  secretion  does  not 
always  cause  blennorrhoea,  but  ma}'4ead  to  diphtheritis.  Climate 
has  a  decided  influence  upon  the  frequency  of  diphtheritis.  In 
North  Germany  it  is  quite  frequently  seen,  while  in  Vienna*  it  is 
one  of  the  rarest  of  all  diseases  of  the  eye. 

In  cases  where  the  affection  is  at  first  unilateral,  the  first  step 


*  Bericht  iiber  die  Wiener  Augenklinik,  Wien,  1867,  pag.  44. 


SWELLI^^C^   OF   THE   COXJUNCTIVAI.    FOLLICLES.  271 

in  the  treatment,  just  as  in  acute  blennorrhoea,  is  to  cover  the 
healthy  eye  by  a  protective  bandage.  It  is  true  this  does  not 
always  succeed. 

In  the  beginning  of  tlie  disease  the  treatment  is  strictly  anti- 
phlogistic, the  principal  reliance  being  placed  on  ice-water  dress- 
ings. Still,  cases  do  occur  in  which  these  applications  are  not 
well  borne,  but  where  warm  fomentations  act  more  favorably. 

Among  other  remedies  recommended  are  copious  bleeding  by 
means  of  leeches,  the  splitting  of  the  outer  canthus,*  deep  incisions 
in  that  jmrt  of  the  conjunctiva  infiltrated  by  the  dij)htheritic  ex- 
udate,f  and  rapid  mercurialization  by  calomel  and  the  inunction 
of  gray  ointment. 

There  is  no  doubt  whatever  that  cauterization  of  the  conjunc- 
tiva during  the  diphtheritic  stage  should  be  absolutely  avoided. 
And  in  general  the  indications  for  the  use  of  caustics  in  this  disease 
must  be  more  carefully  considered  than  in  blennorrhoea.  No  local 
treatment  is  indicated  till  the  diphtheritic  exudate  is  completely 
absorbed,  the  mucous  membrane  swollen,  but  relaxed  and  yield- 
ing a  ])urulent  secretion  ;  then  the  application  of  a  ^  to  1  per  cent, 
solution  of  nitrate  of  silver  may  be  begun,  increasing  gradually 
to  a  2  or  3  per  cent,  solution.  In  other  respects  the  genei'al  rules 
for  the  treatment  of  blennorrhoea  are  applicable. 

In  those  cases  in  which  the  disease  passes  immediately  over 
from  the  first  stage  to  recovery,  no  local  treatment  whatever  of 
the  conjunctiva  is  indicated. 

The  treatment  of  corneal  affections  is  the  same  as  in  blennorrhoea. 

SWELLING   OF   THE    CONJUNCTIVAL    FOLLICLES. 

One  often  sees  upon  the  conjunctiva,  especially  on  the  temporal 
half  of  the  fornix  of  the  under  lid,  small,  bright,  semi-transparent, 
superficial  and  slightly  prominent  vesicles.  Their  number  may 
be  very  small  and  limited  to  the  under  lid  ;  when  more  numerous 
they  occur  also  oil  the  upper  lid,  and  in  that  case  first  near  the 
median  angle,  or  they  may  become  so  numerous  as  to  occupy  the 
entire  conjunctiva  palpebrarum.  They  are  then  generally  sparse 
and  small  on  the  tarsal  part  and  more  numerous  at  the  fornix,  so 

*  Von  Graefe,  Arch.  f.  Ophtli.,  B.  vi.  2,  pag.  123. 
f  Jacobson,  Arch.  f.  Ophth.,  B.  vi.  2,  pag.  203. 


272  SWELLING    OF    THE    CONJUNCTIVAL    FOLLICLES. 

that  they  appear  like  several  strings  of  pearls  one  behind  the  other. 
The  largest  of  these  bodies  are  oval,  their  longest  axis  parallel  to 
the  palpebral  fissure,  and  measuring  something  more  than  1  mm. 
Frequently,  where  their  numbers  are  very  great,  similar  vesicles 
are  found  on  the  scleral  conjunctiva  near  the  fornix. 

The  pathological  anatomy  of  these  so-called  "  vesicular  granu- 
lations" was  asserted  by  Stromeyer*  to  consist  in  obstruction  of  the 
follicles  of  the  conjunctiva.  As  this,  however,  has  lately  appeared 
to  be  doubted,  I  have  repeatedly  taken  occasion  to  examine 
freshly  excised  portions  of  the  conjunctiva  with  special  reference 
to  it.  Prof.  W.  Krause,  whose  accurate  investigations  on  this  ' 
subject  have  contributed  much  to  onr  understanding  of  it,  had 
the  kindness  to  examine  at  the  same  time  most  of  these  prepara- 
tions, and  we  can  both  say  that  in  these  cases  the  objects  in  question 
were  SM'ollen  conjunctival  follicles.  These  follicles  ap])ear  under 
the  microscope  as  oval  or  spherical  bodies,  having  a  caj^sule  of 
connective  tissue,  with  a  diameter  seldom  greater  than  0.5  mm. 
As  components  of  the  follicle  one  may  recognize,  besides  the  in- 
distinct fibrous  capsule,  a  delicate  reticulation  of  connective-tissue 
fibres,  in  whose  meshes  lie  lyrapli  corpuscles  and  free  nuclei.  The 
lymph  follicles  are,  moreover,  permeated  by  fine  capillaries,  which 
are  continuous  with  the  vascular  net  surrounding  the  capsule. 
There  is  also  a  small  number  of  nerve  fibres.  Finally,  Frey 
demonstrated  between  and  upon  the  follicles,  an  intricate  lym- 
phatic net-work,  so  that  it  can  no  longer  be  doubted  that  these 
bodies  belong  to  the  lymphatic  system. 

This  circumstance  deserves  special  mention,  that,  upon  anatom- 
ical examination,  generally  only  a  small  number  of  conjunctival 
follicles  are  found,  while  during  life  we  often  see  the  whole  con- 
junctiva covered  with  them.  Still,  from  this  fact  there  is  no  cer- 
tainty that  new  follicles  are  formed,  since  all  the  follicles  which 
exist  are  not  necessarily  anatomically  demonstrable.  It  is  evident 
that  the  development  of  these  structures  in  general,  not  only  on 
the  conjunctiva  but,  for  instance,  upon  the  walls  of  the  intestines, 
even  under  physiological  relations,  depends  upon  conditions  not 
fully  understood.  The  theory  that  the  lymph  follicles  are  not 
physiological   organs   but  pathological    products,  depends  partly 

*  Deutsche  Klinik,  1859,  pag.  247. 


SWELLING   OF   THE    CONJUNCTIVAL    FOLLICLES.  273 

upon  this  change  in  their  appearance.  There  is  no  direct  proof 
to  substantiate  this  theory.  To  call  all  conjunctival  follicles  tra- 
choma and  to  assume  the  existence  of  trachoma  from  the  presence 
of  follicles  may  be  very  convenient,  but  it  does  not  advance  our 
knowledge  either  of  the  conjunctival  follicles  or  of  the  nature 
of  trachoma.  Clinical  observation  has  at  least  determined  this 
much  with  certainty,  that  swelling  of  the  conjunctival  follicles 
may  exist  and  continue  a  long  time  without  the  development 
of  the  slightest  trace  of  trachoma. 

Unfavorable  hygienic  surroundings  seem  the  most  frequent 
cause  of  this  follicular  swelling.  It  occurs  also  frequently  in 
individuals  whose  general  surroundings  are  good,  but  who  period- 
ically occupy  overcrowded  apartments,  badly  ventilated  school-  or 
sleeping-rooms,  etc.  The  same  circumstances,  of  course,  favor  the 
contagious  spread  of  a  muco-purulent  conjunctivitis  occurring  in 
one  of  these  individuals,  either  accidentally  or  from  these  very 
causes.  It  is  frequently  the  case,  though  it  should  not  be  so,  that 
the  common  use  of  wash-basins,  towels,  etc.,  gives  sufficient  oppor- 
tunity for  direct  inoculation.  But  even  where  this  is  not  the  case 
the  disease  may  spread,  as  an  endemic,  in  a  manner  only  to  be 
explained  by  assuming  an  atmospheric  infection. 

Its  course  varies  considerably.  Simple  swelling  of  the  con- 
junctival follicles  may  persist  a  long  time  in  spite  of  the  most 
careful  treatment.  It  often  disappears  under  the  use  of  an  astrin- 
gent eye-water,  for  instance,  a  ^  per  cent,  solution  of  sulphate  of 
zinc. 

The  other  symptoms  connected  with  this  condition  depend  for 
the  most  part  upon  the  behavior  of  the  raucous  membrane.  The 
patients  often  experience  no  annoyance,  and  the  discovery  of  the 
follicles  is  accidental.  In  other  cases  the  mucous  membrane  pre- 
sents the  symptoms  of  a  simple  hyperaemia,  and  the  patients 
complain  of  burning  and  pricking  in  the  eyes,  especially  during 
work,  and  perhaps  that  upon  waking  in  the  morning  the  lids  are 
glued  together.  Even  when  the  entire  conjunctiva  of  the  lids  is 
covered  with  swollen  follicles,  there  iriay  be  no  further  symptoms 
than  those  named.  Swelling  of  the  follicles,  however,  appears  to 
make  the  conjunctiva  more  susceptible  to  inflammation ;  and  this 
much  is  certain,  that  all  conjunctival  inflammations,  under  these 
circumstances,  are  very  obstinate.     Moreover,  all  forms  of  con- 


274  SWELLING   OF   THE    CONJUNCTIVAL    FOLLICLES. 

junctivitis,  chronic  hyperemia,  simple,  blennorrhoeal.  or  phlyc- 
tenular conjunctivitis,  may  be  complicated  with  swelling  of  the 
conjunctival  follicles. 

A  very  peculiar  condition  develops  when  swelling  of  the  fol- 
licles becomes  complicated  by  severe  inflammation  and  a  muco- 
purulent secretion.  The  clear,  transparent  color  of  the  follicles 
then  disappears,  principally  because  the  mucous  membrane  cover- 
ing them  becomes  more  opaque;  moreover,  their  sharp  outlines 
are  lost  in  the  swelling  of  the  mucous  membrane;  still,  we  can 
detect  upon  the  folds  of  the  thickened  conjunctiva,  traces  of  the 
follicles.  Especially  in  those  cases  in  which  the  conjunctivitis 
is  unilateral,  while  the  swelling  of  the  follicles  exists  on  both 
sides,  is  the  comparison  of  the  two  eyes  very  instructive. 

Cases  of  follicular  swelling  which  become  complicated  with 
mild  conjunctivitis  are  difficult  to  distinguish  from  those  which 
are  generally  described  as  "acute  granulations."  Besides  the 
symptoms  of  an  acute  inflammation,  the  mucous  membrane  is 
found  covered  with  small  spherical  prominences,  smaller  and 
fewer  upon  the  tarsal  part,  larger  and  more  numerous  in  the 
fornix.  In  more  severe  cases  the  margins  of  the  lids  are  red  and 
swollen.  The  hypersemia  of  the  mucous  membrane  is  frequently 
so  excessive  that,  upon  everting  the  lids  or  lightly  touching  them, 
bleeding  follows.  Th^  conjunctiva  sclerse  is  often  infiltrated  with 
a  serous  exudation,  and,  as  a  special  peculiarity,  the  cornea  is 
often  surrounded  by  a  zone  of  injected,  radiating,  fine,  deep-lying 
vessels.  The  secretion  is  at  first  a  thin  fluid,  consisting  of  copious 
tears  with  some  coagulated  mucus;  later,  it  becomes  muco-puru- 
lent  and  less  profuse.  There  is  the  same  tendency  to  severe 
corneal  affections  as  in  the  blennorrhoeal  process. 

It  need  scarcely  be  remarked  that  the  conjunctival  follicles 
ought  never  to  be  destroyed  by  cauterization.  The  local  treat- 
ment should  be  regulated  by  the  condition  of  the  mucous  mem- 
brane. If  the  latter  be  simply  hypersemic,  fresh  air,  frequent 
washing  of  the  eyes  in  cold  water,  the  eye-douche,  etc.,  should  be 
prescribed.  If  there  be  at  the  same  time  an  abnormal  secretion, 
mild  astringent  eye-washes  should  be  used,  for  instance,  a  ^  per 
cent,  solution  of  sulphate  of  zinc  or  neutral  acetate  of  lead. 

Swelling  of  the  conjunctival  follicles  complicated  with  consid- 
erable blennorrhoeal  swelling  of  the  raucous  membrane  demands 


TRACHOMA.  275 

at  first,  antiphlogistic  treatment,  and,  later,  cauterization  with  a 
1  to  3  per  cent,  solution  of  nitrate  of  silver.  Still,  the  caustic 
treatment  must  be  undertaken  with  great  caution,  since  premature 
and  severe  cauterizations  are  likely  to  cause  dangerous  exacer- 
bations. So,  too,  the  cauterizations  should  be  stopped,  and  an 
antiphlogistic  treatment  substituted,  so  soon  as  any  intercurrent 
inflammation  appears.  After  it  has  passed,  the  caustic  treatment 
may  be  again  carefully  begun. 

If  the  above  described  conjunctival  affections  spread  epidem- 
ically in  schools,  barracks,  etc.,  the  diseased  should  be  separated 
from  the  well,  and  the  unfavorable  hygienic  surroundings  which 
usually  exist  should  be  improved  as  much  as  possible. 

TEACHOMA. 

At  first  glance,  it  would  seem  strange  that  a  general  understand- 
ing of  so  frequent  a  disease  as  trachoma  has  not  yet  been  reached. 
But  it  is  true,  for  the  same  reasons  that  confusion  of  ideas  prevails 
in  other  branches  of  medicine.  How  different,  for  instance,  would 
be  the  understanding  of  syphilis  if  it  were  possible  to  follow  each 
case  through  its  entire  course !  In  the  same  way  we  may  account 
for  the  many  deficiencies  and  obscurities  existing  in  our  under- 
standing of  trachoma.  Not  only  are  the  opportunities  for  ana- 
tomical examinations  in  recent  cases  very  rare,  but,  what  is  still 
more  unfortunate,  the  clinical  observations  remain  often  very 
imperfect.  On  account  of  the  exceedingly  chronic  nature  of  the 
disease,  it  is  very  seldom  possible  to  follow  any  individual  case 
from  beo-innino;  to  end.  The  difficulties  are  still  further  in- 
creased  by  the  fact  that  processes  which  at  first  appear  very  dif- 
ferent may  lead  to  the  same  results,  namely,  shrinking  of  the 
conjunctiva  and  tarsus,  and  pannus  of  the  cornea.  In  general, 
we  must  class  as  trachoma  all  cases  which  begin  insidiously, 
whose  course  is  chronic,  and  which  finally  lead  to  shrinking  of 
the  conjunctiva. 

In  many  cases  trachoma  develops  in  the  following  manner.  The 
entire  surface  of  the  conjunctiva  is  at  first  observed  to  be  strewed 
M'ith  spherical,  yellow,  opalescent  granulations,  standing  so  near 
together  that  they  have  been  compared  to  frog's  spawn.  Upon 
everting  the  lid  the  fornix  comes  prominently  to  view,  swollen 
into  thick    folds,  and   covered  with  trachomatous  granulations. 


276  TRACHOMA. 

These  changes  may  cause  a  veiy  considerable  hypertrophy  of  the 
plica  semilunaris,  which  then  projects  over  the  lachrymal  caruncle 
in  the  form  of  a  yellow  fold.  Scattered  granulations  also  generally 
appear  upon  the  conjunctiva  scler£e,  near  the  fornix. 

If  one  of  the  spherical  granulations  be  removed  with  the  scis- 
sors for  the  purpose  of  microscopic  examination,  there  is  found 
immediately  under  the  epithelium  an  accumulation  of  cells  having 
exactly  the  character  of  lymph-  or  white  blood-corpuscles.  Among 
these  cells  run  very  delicate  blood-vessels,  and  upon  the  surface, 
immediately  under  the  epithelium,  are  generally  a  number  of  fatty 
degenerated  cells,  which  possibly  cause  the  yellow  appearance  of 
the  trachomatous  granulations.  Smaller  bodies  of  this  sort,  of 
perhaps  1  mm.  diameter,  which  I  have  occasionally  examined, 
appear  to  be  enveloped  by  a  closed  capsule  of  connective  tissue, 
and  should  therefore  be  regarded  as  lymph  follicles,  but  as  a  gen- 
eral thing  the  larger  of  these  bodies  do  not  possess  the  most  essen- 
tial characteristic  of  a  lymph  follicle,  namely  a  connective-tissue 
capsule  separating  it  from  the  surrounding  tissues.  The  accumu- 
lated lymphoid  cells  which  give  the  yellow  color  to  the  granulations 
are  by  no  means  strictly  limited  to  them.  Their  limits  are  gradu- 
ally lost  in  the  adjoining  conjunctival  tissue,  where  they  are  more 
sparsely  scattered.  This  is  why  frequently  extensive  portions  of 
the  conjunctival  tissue  are  found  infiltrated  with  these  yellow-gray 
masses,  and  still,  none  of  the  above  described  trachomatous  granu- 
lations are  present. 

This  condition  may  exist  without  any  subjective  symptoms  by 
which  the  patient  becomes  aware  of  it.  Generally,  however,  in- 
flammatory attacks  occur  sooner  or  later,  in  the  course  of  which 
corneal  disease  (Pannus  trachomatosus)  develops.  Still,  this  con- 
dition is  one  from  which  there  may  be  full  recovery.  I  have  seen 
cases  in  which  the  conjunctiva  presented  the  above  described 
macroscopic  and  microscopic  appearances  and  the  cornea  a  con- 
siderable trachomatous  })annus,  and  yet  recovery  was  so  complete 
that  no  changes  could  be  seen  in  the  conjunctiva,  and  in  the 
cornea  only  a  superficial,  diffuse  clouding.  Still,  such  a  favorable 
course  is  comparatively  rare. 

The  intercurrent  inflammations  are  often  very  severe.  Great 
swelling  of  the  lids  comes  on  suddenly  ;  they  are  red,  glistening,  and 
hot;  the  conjunctiva  is  swollen,  smooth,  glistening,  and  very  red; 


TRACHOMA.  277 

the  vsecretion  is  very  profuse,  consisting  of  tears  mixed  with  mucus. 
Keratitis  is  frequently  present.  The  eyes  are  very  sensitive  to 
light ;  the  liead  is  held  bent  forward ;  the  attempt  to  separate  the 
lids  forcibly  is  exceedingly  painful,  and  causes  violent  spasmodic 
contractions  in  them.  If  the  conjunctiva  be  carefully  examined 
after  the  severe  inflammatory  symptoms  have  abated,  it  will  be 
found,  especially  on  the  tarsal  part  of  the  upper  lid,  in  a  condition 
resembling  the  granulating  surface  of  a  wound.  It  is  covered 
with  growing  nodules,  which  are  exceedingly  hypersemic  and 
painful,  and  which  bleed  if  lightly  touched. 

It  cannot  be  determined  whether  this  condition  is  always  pre- 
ceded by  the  above  mentioned  frog-spawn  granulations  or  the 
diifuse  infiltration  of  the  mucous  membrane,  since  many  patients 
do  not  present  themselves  for  treatment  till  the  disease  has  reached 
this  stage. 

If  the  disease  has  once  reached  this  condition,  the  formation  of 
cicatricial  tissue  and  more  or  less  shrinkage  of  the  conjunctiva 
always  follow.  The  conjunctiva  then  appears  smooth,  presenting 
no  longer  the  soft,  velvety  surface  of  a  normal  mucous  membrane, 
but  is  changed  as  is  the  skin  by  the  formation  of  an  extensive 
cicatrix.  There  are  generally  strong  strings  of  cicatricial  tissue 
on  the  tarsal  part  of  the  upper  lid,  parallel  to  its  margin,  and 
about  2  mm.  from  it.  The  fornix  also  is  smooth  and  shortened, 
so  that  when  the  louver  lid  is  everted  and  the  patient  looks  up- 
ward a  number  of  vertical  folds  are  seen  to  stretch  from  the 
scleral  to  the  palpebral  conjunctiva.  The  same  can  be  seen  on  the 
upper  lid  when  the  patient  looks  downward.  The  margin  of  the 
lids  and  the  cilia  may  remain  normal,  but  as  a  rule  the  shrinking 
is  not  limited  to  the  conjunctiva,  but  extends  to  the  tarsus.  The 
effect  of  this  is  to  obliterate  the  inner  angle  of  the  lid,  and  an 
abnormal  direction  is  given  to  the  cilia.  The  tarsus  becomes  too 
much  curved,  both  in  the  vertical  and  in  the  horizontal  direction, 
and  its  anterior  convex  aspect  causes  the  lid  to  appear  swollen  ; 
an  examination  of  the  inner  surface  suffices  to  clear  up  this  error. 
The  nutrition  of  the  cilia  suffers  from  the  disease  of  the  tissues 
about  their  roots.  They  become  replaced  by  poorly  developed,  thin 
hairs,  which  are  often  abnormal  in  position  and  direction,  resting 
upon  the  cornea  and  keeping  up  a  continual  mechanical  irritation. 
The  consequence  may  be  a  sj)asmodic  contraction  of  the  marginal 


278  TRACHOMA. 

portion  of  the  orbicularis,  which  causes  the  cilia  to  turn  absolutely 
inward  (trichiasis,  distichiasis,  and  entropion). 

Whether  a  condition  of  proliferation  always  precedes  this 
shrinkage  of  the  conjunctiva  cannot  be  absolutely  asserted. 

In  the  worst  cases  the  shrinkage  of  the  conjunctiva  finally 
becomes  so  great  that  it  loses  the  character  of  a  mucous  membrane. 
The  excretory  ducts  of  the  lachrymal,  tarsal,  and  conjunctival 
glands,  and  the  hair  follicles,  become  obliterated,  and  thus  all 
those  organs  are  destroyed  which  serve  to  moisten  the  mucous 
membrane.  Its  epithelium  becomes  dry,  and  therefore  appears 
gray  like  the  epidermis.  The  same  condition  exists  on  the  cornea, 
which  is  of  course  absolutely  opaque.  The  shrinkage  of  the 
mucous  membrane  is  often  so  great  that  the  margins  of  tiie  lids 
are  drawn  close  about  the  margin  of  the  cornea,  so  that  a  conjunc- 
tival sac  no  longer  exists.  This  condition  of  atrophy  and  dryness 
of  the  conjunctiva  is  called  xerosis. 

The  disease  of  the  cornea  which  so  often  accompanies  trachoma 
deserves  special  mention.  Daily  experience  contradicts  the  view 
here  and  there  expressed  that  the  implication  of  the  cornea  is 
simply  the  mechanical  consequence  of  the  trichiasis,  or  of  the 
roughness  of  the  inner  surface  of  the  lids.  Panuus  trachomatosus 
occurs,  and  that,  too,  not  infrequently,  where  the  margins  of  the 
lids  are  normal,  and  where  there  is  no  unevenness  of  the  inner 
surface  of  the  lids. 

Frequently  a  cloudiness  and  vascularization  develop,  beginning 
at  the  upper  corneal  margin.  Large  vessels  jjass  from  the  con- 
junctiva sclerae  over  into  the  superficial  layers  of  the  cornea  and 
there  ramify,  while  the  corneal  tissue  within  the  region  of  this 
vascularization,  and  generally  somewhat  beyond  it,  appears  clouded 
and  frequently  filled  with  a  great  number  of  somewhat  brighter 
gray  dots.  Upon  focal  illumination  the  surface  appears  uneven 
as  if  stippled, 'or  as  if  there  had  been  extensive  superficial  loss  of 
substance.  The  longer  the  process  the  more  the  clouding  extends 
downward,  till  finally  in  this  way  the  whole  cornea  loses  its  trans- 
parency. In  this  form  of  pannus,  too  much  importance  has  been 
attached  to  the  fact  that  the  development  of  vessels  takes  place 
from  above  downward.  Pannus  and  vascularization  of  the  upper 
portion  of  the  cornea  occur  without  trachoma,  and  even  with 
trachoma  it    is   characteristic  only  as   it   involves  a  very  small 


TRACHOMA.  279 

portion  of  the  cornea.  The  more,  however,  the  vascularization 
extends  over  the  cornea,  the  more  this  peculiar  characteristic  dis- 
appears, since  these  vessels  may  encroach  upon  the  cornea  from 
every  part  of  the  margin. 

This  is  still  more  the  case  with  pannus  occurring  in  a  diiferent 
manner.  There  occur  very  often  with  trachoma,  either  with  or 
without  pre-existing  pannus,  circumscribed  corneal  infiltrations 
which  present  fully  the  character  of  a  keratitis  phlyctenulosa. 
They  are  at  first  greatly  distended,  elevated  above  the  general 
surface  of  the  cornea,  of  a  gray  color,  and  surrounded  by  a  diffuse 
clouded  zone.  Somewhat  later  the  more  prominent  part  of  the 
infiltration  breaks  down,  and  a  small  corneal  ulcer  is  formed, 
which  may  perforate  the  cornea  and  cause  anterior  synechia  of  the 
iris.  Extensive  ulceration  of  the  cornea  with  great  prolapsus 
iridis  is  less  frequent.  Often  these  infiltrations  and  ulcers  cause 
a  chronic  irritable  condition.  They  become  vascularized  from 
the  corneal  margin,  and  in  this  manner,  by  a  repetition  of  the 
process,  pannus  is  produced. 

Simultaneously,  the  protracted  hyperemia  of  the  cornea  may 
extend  to  the  iris  and  cause  an  iritis,  which  in  such  a  case  is  hard 
to  recognize  on  account  of  the  cloudiness  of  the  cornea.  Gen- 
erally, however,  upon  using  atropine  and  by  focal  illumination, 
the  cornea  is  still  transparent  enough  to  admit  of  seeing  adhesions 
which  may  have  formed  between  the  margin  of  the  pupil  and  the 
capsule  of  the  lens. 

The  pathological  changes  in  the  cornea  in  pannus  trachomatosus 
consist  in  the  development  of  blood-vessels  and  the  proliferation 
of  countless  spindle-shaped  cells.  Ritter*  found  this  proliferation 
of  cells  beneath  the  anterior  layers  of  the  cornea,  and  in  the  neigh- 
borhood of  the  sclerotic,  penetrating  as  far  as  the  membrane  of 
Descemet,  while  in  the  centre  the  clouded  portion  of  the  cornea 
occupied  only  about  one-eighth  its  entire  thickness  and  was  sharply 
differentiated  from  the  apparent  normal  portion  below.  In  one  case 
which  I  examined,  where  the  pannus  had  been  of  a  high  degree 
and  long  protracted,  the  anterior  elastic  membrane  was  nearly 
entirely  destroyed  by  numerous  superficial  ulcers,  some  of  which 
had   been  already  covered  with  new  epithelium.     The  clouded 

*  Arch.  f.  Ophth.,  B.  vi.  1,  pag.  356. 


280  TRACHOMA. 

portion  occupied  about  one-third  the  thickness  of  the  cornea,  and 
consisted,  just  as  in  the  case  described  by  Ritter,  of  crowded 
spindle-shaped  cells,  among  which  could  be  seen  but  very  little 
transparent  intercellular  substance. 

This  thinning  of  the  intercellular  substance  explains  why  in 
many  cases  of  pannus  the  cornea  assumes  an  abnormal  curvature. 

The  causes  of  trachoma  are  to  be  sought  for  principally  in 
unfavorable  hygienic  surroundings.  Badly  ventilated  and  over- 
filled dwelling-rooms,  barracks,  schools,  factories,  etc.,  can  either 
cause  trachoma  in  a  conjunctiva  previonsly  healthy,  or  can  give  to 
a  somewhat  protracted  conjunctival  inflammation  a  trachomatous 
character.  But  certain  forms  of  keratitis,  especially  those  which 
depend,  as  do  most  phlyctenular  processes,  upon  unfavorable  hygi- 
enic surroundings,  may,  under  the  above  named  deleterious  influ- 
ences, become  complicated  with  trachoma.  The  contagious  char- 
acter of  the  secretions  in  acute  inflammatory  attacks  is  undoubted. 
Inoculated  conjunctivitis  may  vary  greatly  in  severity,  and  may 
even  assume  a  blennorrhceal  character.  Generally,  however,  at  the 
time  of  the  inoculation  the  patient  is  subjected  also  to  the  above 
named  hurtful  influences,  and  a  trachomatous  character  is  thereby 
conditioned. 

Trachoma  is  less  frequent  in  children  than  in  adults,  but  there 
is  no  truth  in  the  asserted  immunity  of  childhood  from  the  disease. 

Ife  is  noticeable,  further,  that  geographical  causes  affect  the  dis- 
ease. Low,  damp  lands  appear  favorable  to  trachoma,  while  in 
mountainous  regions  it  is  much  less  frequent.  Switzerland,  for 
instance,  is  said  to  be  entirely  free  from  trachoma. 

The  course  and  result  in  many  mild  cases  of  trachomatous 
disease  are  quite  favorable.  Recovery  takes  place  either  sponta- 
neously or  under  proper  treatment  before  cicatricial  contraction 
of  the  conjunctiva  or  pannus  has  developed.  In  other  cases  the 
process  does  notecase  till  theconjunctiv^a  has  shrunk  to  somewhat 
less  than  its  normal  extent  and  has  assumed  a  peculiar  smooth 
appearance.  If  the  position  of  the  margin  of  the  lids  and  the 
direction  of  the  cilia  remain  normal,  there  may  be  no  annoyances 
connected  with  this  condition ;  but  in  some  cases  such  patients 
suffer  from  frequent  relapses  of  conjunctival  hypersemia.  If,  how- 
ever, trichiasis  and  entropion  have  developed,  the  continual  me- 
chanical irritation  of  the  cornea  and  conjunctiva  thereby  caused 


TRACHOMA.  281 

excites  constant  inflammation.     Fortunately,  most  of  these  eases 
may  be  greatly  benefited  by  an  operation. 

Finally,  in  many  cases  not  even  relative  recovery  is  attained. 
The  patients,  even  after  cicatricial  contraction  of  the  conjunctiva, 
are  exposed  throughout  their  lives  to  attacks  of  inflammation, 
beginning  sometimes  on  the  conjunctiva,  sometimes  on  the  cornea. 
Generally,  incurable  blindness  follows,  due  to  the  clouding  or 
ulceration  of  the  cornea,  or  to  xerotic  shrinkage  of  the  entire 
conjunctival  sac. 

Treatment. — In  the  first  ])lace  the  hygienic  relations  are  to  be 
improved  as  much  as  possible,  and  all  means  employed  to  ^irevent 
the  spread  of  the  disease. 

The  local  treatment  of  the  mucous  membrane  is  modified  by  its 
condition,  and  accordingly  all  the  remedies  ever  employed  in  con- 
junctival inflammations  may  be  used  in  their  proper  place  in  the 
treatment  of  trachoma.  Above  all  things  one  must  rid  himself 
of  the  idea  that  it  is  desirable  to  destroy  by  caustics  the  ex- 
crescences upon  the  surface  of  the  conjunctiva.  The  use  of  all 
local  means  should  be  with  the  object  of  altering  the  nutrition  of 
the  mucous  membrane ;  all  destructive  effects  must  carefully  be 
avoided. 

In  those  cases  of  trachoma  which  present  the  above  described 
peculiar  yellow-gray  exudation  in  the  mucous  membrane,  or  in 
which  the  conjunctiva  has  upon  its  surface  hypersemic  excrescences, 
which  incline  to  bleed  easily,  sulphate  of  copper  is  the  sovereign 
remedy.  The  conjunctiva  may  be  touched  with  a  pencil  of  the 
pure  crystal,  or  solutions  of  varying  strength  up  to  10  ])er  cent, 
may  be  used.  These  are  applied  with  a  camel-hair  brush,  and 
then  immediately  washed  off  again.  In  most  cases,  rapid  im- 
provement takes  place  under  this  treatment.  It  is  generally  ad- 
visable to  prescribe  the  continual  use,  for  some  time,  of  a  salve 
consisting  of  1  to  1^  parts  sulphate  of  copper  to  100  parts  unguen- 
tura  glycerini.  If  the  sulphate  of  copper  be  not  well  borne,  or  if 
it  do  not  produce  the  wished-for  results,  a  1  or  2  per  cent,  solu- 
tion of  nitrate  of  silver  should  next  be  tried.  A  still  milder 
effect  may  be  had  by  using  a  1  or  2  per  cent,  solution  of  acetate 
of  lead  or  tannic  acid.  Frequently  the  conjunctiva  is  so  sensitive 
that  local  applications  are  not  well  borne,  but  always  cause  an 
aggravation  of  the  irritable  condition.     In  such  cases  it  is  well  to 

19 


282  TRACHOMA. 

use  warm  fomentations,  either  cataplasms  or  warm  vapor  directed 
against  the  eye.  When  under  this  treatment  a  copious  muco- 
purulent secretion  occurs,  the  use  of  mild  local  applications  may 
be  begun. 

If  in  the  later  stages  of  trachoma,  when  the  conjunctiva  has 
become  smooth  and  shrunken,  there  be  still  hypersemia  and  a 
muco-purulent  secretion,  only  mild  local  applications  are  suitable, 
say  a  1  per  cent,  solution  of  nitrate  of  silver,  or  a  1  to  2  per  cent, 
solution  of  acetate  of  lead,  or  an  eye-water  containing  ^  per  cent, 
acetate  of  lead. 

As  already  said,  trichiasis  and  entropion  are  to  be  relieved  by 
operation.  If  only  a  few  small  cilia  have  an  abnormal  direction, 
and  rest  against  the  cornea,  it  is  better  to  pull  them  out  as  often 
as  necessary. 

The  pannus  trachomatosus  appears  generally  directly  dependent 
upon  the  behavior  of  the  conjunctiva,  and  improves  at  the  same 
time  that  it  does.  On  the  other  hand,  it  sometimes  happens  that 
tlie  conjunctiva  becomes  shrunken,  but  is  entirely  free  from  in- 
flammatory irritation,  while  the  pannus  persists  unchanged.  It 
is  useless  in  these  cases  to  continue  the  usual  local  treatment  of 
the  conjunctiva.  The  treatment  is  to  be  ap})lied  directly  to  the 
cornea.  In  such  cases  the  use  of  spray  is  greatly  to  be  recom- 
mended. The  spray  of  a  1  per  cent,  solution  of  sulphate  of  cop- 
per should  be  thrown  for  some  minutes  directly  against  the 
cornea.  A  dilute  solution  of  tincture  of  opium  (one  part  to 
three  of  distilled  water)  often  does  good  service.*  Frequently 
the  keratitis  maintains  an  irritable  condition,  which  demands 
the  use  of  atropine.  If  in  the  later  stages,  when  the  cicatrized 
conjunctiva  has  already  shrunken,  the  keratitis  excite  irritability, 
a  salve  of  red  precipitate,  1  part  to  100  parts  ung.  glycerini,  is 
often  serviceable. 

As  a  last  resort  in  the  most  severe  cases  of  trachoma,  the  inocu- 
lation of  blennorrhceal  or  gonorrhoeal  secretion  in  the  conjunctival 
sac  is  recommended.  There  follows  then  a  blennorrhceal  inflam- 
mation, whose  acute  stage  lasts  from  2  to  6  weeks,  while  a  chronic 

*  Schenkl,  Anwondung  des  Pulverisateurs  bei  Augenkranknngen,  Prager 
Vierteljahrschrift,  1871,  pag.  149  ;  Jules  Cyr,  Note  sur  la  Pulverisation  ap- 
pliquee  aux  Maladies  des  Yeux,  Annales  d'Oculistiquc,  1866,  pag.  232. 


ophthal:mia  geanulosa.  283 

blennorrhceal  condition  may  last  from  2  to  20  months  longer. 
There  should  be  no  treatment  other  than  cleanliness  and  careful 
bathing  of  the  eyes,  since  the  destruction  of  the  trachomatous 
groAvths  and  the  cure  of  the  pannus  depend  upon  the  undis- 
turbed course  of  the  blennorrhceal  process.  The  clearing  up  of 
the  pannus,  moreover,  occurs  very  slowly,  so  that  one  or  two  years 
may  elapse  before  a  definite  effect  is  reached.  This  treatment  is 
recommended  for  cases  in  which  the  lids  are  covered  with  thick  tra- 
chomatous growths,  and  the  pannus  of  the  cornea  is  such  that  the 
patient  is  able  only  to  perceive  light  or  to  count  fingers.  If  a  part 
of  the  cornea  be  still  clear,  its  ulceration  is  to  be  feared.  This 
treatment,  therefore,  is  scarcely  to  be  employed  in  cases  in  which 
there  is  blindness  in  one  eye  but  still  useful  vision  in  the  other. 
For  in  the  progress  of  the  inoculated  blennorrhoea  an  accidental 
infection  of  the  other  better  eye  may  easily  occur,  and  the  danger 
here  on  account  of  the  relatively  good  or  absolutely  normal  con- 
dition of  the  cornea  is  much  greater  than  in  the  eye  whose  cornea 
is  already  highly  vascularized.  But,  after  all,  I  cannot  recom- 
mend this  practice.  No  more  seems  to  be  accomplished  by  it 
than  may  be  done  in  a  less  dangerous  way  by  skilful  local 
treatment  of  the  conjunctiva. 

The  conjunctival  diseases  which  occur  as  epidemics  or  endemics 
in  the  army,  and  which  are  called  by  the  names  Ophthalmia  mili- 
taris,  O.  Egyptiaca,  or  O.  granulosa,  should  be  classed  in  one  or  the 
other  of  the  groups  here  described.  A  proper  understanding  of 
this  subject  is  difficult  to  attain,  for  the  reason  that  it  has  been 
usual  to  include  under  the  term  granulations,  all  inequalities  upon 
the  surface  of  the  conjunctiva.  Indeed,  upon  clinical  examina- 
tion, there  is  often  doubt  whether  one  has  before  him  swollen  fol- 
licles, infiltrated  folds  of  the  mucous  membrane,  or  excrescences 
from  the  tissue  of  the  conjunctiva;  even  the  microscopic  results 
fail  to  agree. 

While  Stromeyer*  has  correctly  shown  that  anatomically  the 
so-called  vesicular  granulations  are  the  closed  follicles  of  the 
conjunctiva,  Preussf  regards  them  as  the  products  of  inflam- 
mation, and  compares  them  with  condylomata  of  the  external 


*  Deutsche  Klinik,  1859,  pag.  247. 

f  Berliner  klinische  Wochenschrift,  1869,  pag.  438. 


284  HEMOREHAGE    OF    CONJUNCTIVA,  CEDEMA,  ETC. 

skin,  the  granulation  tissue,  "  caro  luxuriaus"  of  Virchow. 
The  statements  of  Preuss  respecting  the  microscopic  appearances 
assert  nothing  which  cannot  be  referred  to  the  lymph  follicles, 
and  his  remark  that  "  often  when  such  a  granulation  is  seized 
with  the  scissors,  a  thick  pulp  issues  from  it  as  from  a  ruptured 
capsule,"  makes  it  probable  that  they  are  actually  swollen  lymph 
follicles.  When  now  Preuss  goes  on  to  describe  a  proliferation  of 
connective  tissue  and  subsequent  shrinkage  as  a  metamorphosis 
of  the  granulations,  it  is  certainly  not  to  be  doubted  that  such 
processes  frequently  occur  upon  the  conjunctiva,  but  it  is  not 
probable  that  the  lymph  follicles  alone  experience  this  transfor- 
mation. 

The  difficulty  connected  Avith  the  subject  is  that  the  various 
formations  which  are  called  conjunctival  granulations  may  some 
of  tiiem  have  been  originally  anatomically  identical,  but  by  in- 
ternal metamorphosis  have  come  to  be  different,  while  others 
which  seem  similar  were  originally  anatomically  different.  That 
this  last  often  happens  has  been  frecjuently  shown  in  our  discus- 
sion of  conjunctival  diseases. 

Hemorrhages  beneath  the  conjunctiva  sclerse  occur  sometimes  in 
consequence  of  injuries,  sometimes  from  violent  straining, — for 
instance,  frequently  during  whooping-cough, — sometimes  without 
any  perceptible  cause.  They  disappear  spontaneously  in  a  few 
days. 

Oedema  of  the  conjunctiva  sclerse  is  generally  only  a  symptom  of 
some  other  disease.  Acute  conjunctival  inflammation,  severe  iritis 
or  choroiditis,  inflammation  of  the  orbital  fat,  etc.,  may  be  accom- 
panied by  excessive  chemotic  swelling.  Often,  however,  without 
any  apparent  cause,  there  occur  great  swelling  and  hypersemia  of 
the  conjunctiva  sclerse,  which  protrudes  from  the  palpebral  fissure 
as  a  tensely  stretched  dark-red  tumor.  In  the  course  of  one  or 
two  weeks,  if  the  eye  be  kept  quiet  and  protected  from  external 
irritation,  this  erysipelatous  inflammation — if  one  wish  to  call  it 
so — may  disappear. 

In  the  course  of  variola  the  characteristic  pustules  may  develop 
upon  the  conjunctiva.  After  they  are  healed  they  generally  leave 
pigmented  spots. 

The  occurrence  of  lupus  has  already  been  mentioned  on  page 
227. 


PEMPHIGUS.       BtlENS.       PTERYGIUM.  285 

Pemphigus  of  the  conjunctiva  is  very  rare.  Only  two  cases* 
are  known  in  which  pemphigus  occurred  upon  the  conjunctiva  in 
connection  Avith  the  eruption  on  other  parts  of  the  body.  It 
always  leaves  a  scar,  just  as  if  the  surface  had  been  destroyed  by 
a  strong  caustic.  Repeated  eruptions  of  jDemphigus,  therefore, 
greatly  endanger  vision,  by  shrinkage  of  the  conjunctiva  and 
opacity  of  the  cornea  depending  upon  it. 

Foreign  bodies  in  the  conjunctival  sac  generally  fix  themselves 
upon  the  tarsal  part  of  the  upper  lid,  and  cause  an  easily  recog- 
nizable traumatic  conjunctivitis.     Their  removal  is  not  difficult. 

Splinters  of  straw,  wood,  etc.,  often  hide  in  the  fornix  of  the 
upper  lid,  and  may  remain  there  a  long  time.  They  cause  a  cir- 
cumscribed proliferation  of  the  connective  tissue,  which  disappears 
after  the  foreign  body  has  been  removed. 

Burns  of  the  conjunctiva,  by  molten  substances  or  chemical 
caustics,  cause  a  traumatic  conjunctivitis,  which  in  mild  cases  yields 
to  simple  antiphlogistic  treatment,  or  may  pass  over  into  some 
one  of  the  above  described  forms  of  conjunctivitis.  Deep  burns, 
destroying  the  mucous  membrane,  cause  cicatricial  adhesions  and 
symblepharon. 

By  pterygium  is  understood  a  thickening  of  the  conjunctiva,  of 
triangular  form,  its  base  generally  turned  toward  the  inner  can- 
thus,  while  its  white,  glistening,  blunt  point  lies  upon  the  cornea. 
A  number  of  vessels  converging  toward  the  point  can  generally 
be  seen  in  the  pterygium. 

The  base  of  the  pterygium  is  sometimes  only  a  few  millimetres 
from  the  margin  of  the  cornea.  Where  it  has  existed  a  long  time, 
and  has  reached  a  high  degree  of  development,  it  may  extend  to 
the  plica  semilunaris  or  to  the  fornix,  and  this,  on  account  of  the 
non-yielding  nature  of  the  pterygium,  causes  a  limitation  of  the 
movement  of  the  eye. 

Near  its  point  the  borders  of  the  pterygium  are  sharply  defined, 
and  in  the  neighborhood  of  the  limbus  conjunctivse  cornese  they 
are  often  reflected  under,  so  that  a  fine  probe  may  be  inserted  for 
a  short  distance  between  the  pterygium  and  the  cornea.  Toward 
its  base  the  pterygium  gradually  loses  its  sharp  boundaries. 


*  White  Cooper,  Ophth.  Hosp.  Rep.,  1858,  Xo.  4,  pag.  155;   Wceker,  Klin. 
Monatsbl.  f.  Augenheilk.,  1868,  pag.  232. 


286  PTERYGIUM. 

The  connection  between  the  pterygium  and  the  tissue  under  it 
is  quite  loose,  and  it  may  be  removed  with  the  forceps  and  scissors 
from  the  sclera  and  cornea  without  causing  pain  to  the  patient, 
especially  when  he  is  told  to  look  toward  the  side  on  which  the 
pterygium  grows. 

In  the  great  majority  of  cases  the  base  of  the  pterygium  is  di- 
rected toward  the  inner  canthus,  seldomer  outward,  and  only  very 
rarely  upward  or  downward.  The  point  gradually  grows  from 
the  margin  of  the  cornea  toward  the  centre,  but  without  actually 
reaching  it,  except  in  rare  cases. 

Under  the  influence  of  conjunctival  inflammations  the  ptery- 
gium may  swell  greatly  and  assume  a  fleshy,  uneven  appearance. 

Pterygium  occurs  most  frequently  in  aged  persons  who  by  the 
nature  of  their  daily  occupations  are  exposed  to  the  effect  of  me- 
chanical or  chemical  irritants,  for  instance,  dust,  and  particularly 
lime-dust,  or  the  irritating  fumes  of  stables,  etc.  Chronic  con- 
junctivitis often  exists  simultaneously  with  the  pterygium. 

Microscopic  examination*  has  shown  that  the  pterygium  ana- 
tomically is  a  mass  of  connective  tissue,  which  is  to  be  regarded  as 
continuous  with  the  conjunctiva  scleras.  Upon  longitudinal  sec- 
tion the  bundles  of  connective-tissue  fibres  are  seen  converging 
toward  the  point  of  the  pterygium ;  parallel  with  them  run  many 
very  thin-walled  blood-vessels,  which  are  more  numerous  just 
below  the  epithelium  than  in  the  deeper  parts,  where  only  a  few 
large  vascular  stems  are  to  be  found. 

The  connective  tissue  composing  the  inner  part  of  the  pterygium 
is  of  two  kinds,  colloid  or  mucous,  and  fibrillar.  There  is,  how- 
ever, no  sharp  demarcation  between  the  two  kinds  of  tissue,  but 
the  transition  from  one  to  the  other  is  gradual.  The  fibrillar 
tissue  lies  mostly  in  the  central  part,  and  consists  of  fibres  running 
longitudinally,  having  few  nuclei,  and  arranged  in  bundles.  Its 
structure  is  most  dense  at  the  point  and  at  the  outer  sides  of  the 
pterygium,  while  in  the  inner  part  it  lies  only  along  the  course 
of  the  blood-vessels.  The  nearer  its  cells  lie  to  the  vessels  the 
closer  and  more  regularly  are  they  disposed ;  the  farther  they  are 
from  the  vessels  the  sparser  and  longer  they  become,  and  the  more 

*  Schreiter,  Untersuchungen  iiber  das  Fliigelfell,  Inaugural-Dissertation, 
Leipzig,  1872. 


PTERYGIUM.  287 

ap})arent  their  arrangement  in  parallel  bundles.  It  is  especially 
noticeable  that  not  only  the  anterior  surface  of  the  pterygium,  but 
also  that  part  of  its  posterior  surface  which  lies  upon  the  cornea 
is  covered  with  epithelium.  This  gives  to  the  pterygium  the  ap- 
pearance of  being  a  growth  of  that  layer  of  the  conjunctiva  sclerse 
which  lies  between  the  epithelium  and  the  sclera.  The  growth 
and  jirogress  as  well  as  the  triangular  form  of  the  pterygium 
would  then  depend  principally  upon  the  growth  of  the  vessels 
and  their  arrangement. 

These  formations  are  really  different  from  the  somewhat  simi- 
lar ones  which  are  caused  by  loss  of  substance  and  cicatrization 
at  tlie  margin  of  the  cornea,  and  which  have  therefore  been  called 
"cicatricial  pterygium."  Ulcerative  processes  at  the  margin  of 
the  cornea,  involving  both  it  and  the  conjunctiva,  may,  from  the 
resulting  cicatricial  contraction,  end  in  this  kind  of  pterygium. 
The  easily  displaced  conjunctiva  is  drawn  over  upon  the  cornea, 
and  thus  a  triangular,  folded,  thickened  mass  is  formed,  whose 
point  lies  upon  the  cornea,  and  whose  base  extends  to  the  fornix 
conjunctivae.  Wounds  upon  the  margin  of  the  cornea  by  foreign 
bodies,  gunpowder  blown  into  the  eye,  burns  from  mineral  acids 
or  from  molten  metals,  have  been  observed  as  causes.  It  is  only 
exceptionally,  but  in  such  cases  quite  rapidly,  that  cicatricial 
pterygium  occurs  in  consequence  of  acute  conjunctival  blennor- 
rhoea  or  of  phlyctenular  keratitis.  When  it  does  occur  it  differs 
from  the  typical,  slowly  developing  form,  by  being  more  frequently 
directed  upward  than  toward  the  inner  canthus. 

Pterygium  generally  causes  no  inconvenience.  It  is  only  very 
seldom  that  it  attains  such  a  development  as  to  interfere  with 
vision,  or  to  cause  diplopia  by  limiting  the  movement  of  the  eye. 
For  this  reason  the  indication  for  an  operation  seldom  exists. 
Moreover,  the  patients  generally  affected  by  pterygium  are  of  a 
class  very  indifferent  to  the  cosmetic  effects  of  an  operation. 

If  the  pupillary  region  of  the  cornea  be  covered  by  the  ptery- 
gium, the  operation  of  iridectomy  affords  a  good  prospect  for 
improving  vision. 

If  the  removal  of  the  pterygium"  be  indicated,  it  may,  according 
to  Arlt's*  method,  be  performed  by  making  a  rhomboidal  incision. 

*  Augenheilk.,  B.  i.  pag.  163. 


288  PINGUECULA.      TUMORS. 

The  pterygium  is  to  be  grasped  above  the  margin  of  tlie  cornea 
with  the  toothed  forceps ;  its  point  is  tlien  to  be  dissected  with 
the  cataract  knife  as  cleanly  as  possible  from  the  cornea.  The 
pterygium  is  then  loosened  from  the  sclera  by  the  scissors  along 
the  line  of  its  edges  to  a  distance  of  from  2  to  4  mm.  beyond  the 
corneal  margin,  and  dissected  up  as  closely  to  the  sclera  as  possi- 
ble. The  two  diverging  incisions  along  the  edges  are  then  united 
by  two  converging  ones,  thus  giving  to  the  exposed  surface  the 
shape  of  a  rhomboid,  with  one  acute  angle  directed  toward  the 
middle  of  the  cornea  and  the  other  toward  the  equator  of  the  eye. 

If  the  pterygium  be  large,  and  especially  if  of  the  cicatricial 
variety,  the  operation  by  transplantation  is  to  be  recommended, 
since  where  there  is  already  loss  of  substance  it  is  not  advisable 
to  increase  it  by  further  incisions.  The  method  is  as  follows.  The 
point  of  the  pterygium  is  dissected  up  from  the  cornea  and  from 
the  anterior  part  of  the  sclera,  so  that  the  pterygium  can  be  pushed 
back  to  the  fornix  conjunctivae.  The  conjunct! v^a,  above  and  below 
the  wound  thus  made,  is  then  loosened  from  the  sclera  so  that  the 
two  lips  can  be  slid  together  across  the  exposed  sclera  and  fastened 
together  in  that  position  by  sutures. 

Pinguecula  is  the  name  given  to  a  small  yellow  elevation,  having 
its  seat  in  the  conjunctiva  and  subconjunctival  tissue,  near  the 
margin  of  the  cornea,  sometimes  on  the  temporal  and  sometimes 
on  the  median  side.     It  causes  no  annoyances. 

Tumors,  generally  speaking,  do  not  often  develop  upon  the  con- 
junctiva. Among  the  growths  which  occur  upon  the  conjunctiva 
itself  are  first  to  be  mentioned  certain  proliferations  of  the  con- 
nective tissue,  w^hich  are  generally  situated  at  the  inner  angle  of 
the  eye,  near  the  lachrymal  caruncle,  or  even  on  it.  They  are 
round,  varying  from  the  size  of  a  small  pea  to  that  of  a  hazel-nut, 
often  easily  inclined  to  bleed,  and  generally  attached  to  the  con- 
junctiva by  a  thin  pedicle.  They  may  be  easily  removed  and 
subsecjuently  cauterized,  if  necessary.  In  exceptional  cases  these 
growths  show  a  tendency  to  return.*  Similar  connective-tissue 
growths,  which  occur  in  the  conjunctival  wound  made  during  the 
operation  for  squint,  have  already  been  mentioned  on  page  176. 

*  Arlt,  Krankheiten  des  Auges,  B.  i.  pag.  166;  A.  v.  Graefe,  Arch.  f. 
Ophth.,  B.  i.  1,  pag.  293. 


PHLYCTENULAR    CONJUNCTIVITIS.  289 

More  frequently  tujnors  develop  upon  the  margin  of  the  con- 
junctiva, and  spread  from  thence  upon  the  general  conjunctival 
surface,  for  instance,  epithelioma,  from  the  margin  of  the  lids 
(comp.  page  227),  or  the  melanoma,  the  melanosarcoma,  and  the 
dermoid  tumors,  which  generally  originate  on  the  corneo-scleral 
boundary,  and  which  will  be  mentioned  among  the  diseases  of  the 
cornea. 

PHLYCTENULAR    CONJUNCTIVITIS. 

A  very  sharply  defined  group  of  conjunctival  inflammations  is 
characterized  by  the  fact  that  the  inflammatory  process  localizes 
itself  upon  the  conjunctiva  sclerte. 

There  generally  appears  close  to  the  corneal  margin  a  circum- 
scribed papular  swelling,  which  is  commonly  called  a  phlyctenule. 
It  forms  the  point  toward  which  converge  a  number  of  conjunc- 
tival and  subconjunctival  vessels,  which  can  frequently  be  traced 
back  nearly  to  the  fornix. 

As  a  rule,  the  phlyctenules  appear  first  as  papules,  having  a 
diameter  of  from  1  to  2  mm.,  with  turbid  contents.  After  a  short 
time  they  burst,  and  leave  a  shallow  loss  of  substance.  Fre- 
quently several  such  phlyctenules  appear  simultaneously  upon  the 
margin  of  the  cornea.  -  In  many  cases  the  eruption  of  this  in- 
flammation is  accompanied  by  an  acute  swelling  of  the  conjunctiva 
palpebrarum,  with  muco-purulent  secretion.  This  inflammation 
may  be  so  severe  as  to  form  the  most  prominent  symptom  of  the 
disease,  and  the  first  to  demand  treatment. 

Occasionally  in  the  course  of  a  simple  conjunctivitis  there 
occur  a  cii'cumscribed  redness  and  swelling  of  the  conjunctiva 
sclerse,  of  the  size  of  a  pin-head,  and  situated  not  exactly  at  the 
corneal  margin,  but  at  a  little  distance  from  it.  Strictly  speaking, 
this  does  not  belong  to  the  conjunctivitis  phlyctsenulosa  here 
described. 

Another  form,  the  broad  phlyctenular  conjunctivitis,  occurs  in 
the  form  of  flat  infiltrations,  3  to  4  mm.  in  breadth,  crowded 
closely  about  the  cornea,  and  likely  to  cause  purulent  infiltration 
in  it. 

Lastly,  the  small  phlyctenules,  which  occur  in  the  form  of 
numerous  small  papules  upon  the  limbus  conjunctivae  cornes, 
may  just  as  properly  be  called  marginal  keratitis. 


290  PHLYCTEXULAE    CONJUNCTIVITIS. 

In  many  cases  the  process  does  not  go  on  to  the  development  of 
actual  phlyctenules,  but  is  limited  to  a  phlyctenular  injection  at 
the  margin  of  the  cornea. 

The  subjective  symptoms  of  phlyctenular  conjunctivitis  are 
mild,  so  long  as  the  inflammation  is  limited  to  the  conjunctiva 
sclera?,  but  so  soon  as  it  invades  the  cornea  there  occur  those 
violent  irritative  symptoms  so  characteristic  of  keratitis. 

In  simple  cases  of  this  kind  the  causes  are  the  same  as  in  other 
forms  of  conjunctivitis.  Recurring  phlyctenular  conjunctivitis 
generally  exists  in  connection  with  scrofula,  and  is  frequently 
complicated  with  keratitis. 

The  treatment  must,  in  the  first  place,  be  directed  toward  al- 
laying the  existing  irritation.  If  the  inflammation  be  acute,  an 
antiphlogistic  and  mildly  derivative  treatment  is  to  be  employed. 
Cold  dressings  of  fresh  water  or  of  lead-water,  and,  if  necessary, 
mild  cathartics,  are  generally  sufficient.  If  in  consequence  of 
corneal  irritation  there  be  excessive  lachrymation,  photophobia, 
etc.,  atropine  mydriasis  is  to  be  established  and  maintained. 

After  the  irritation  has  been  allayed,  the  mercurial  pre])arations 
are  most  relied  on  in  the  local  treatment.  The  yellow  oxide,  1  to 
1.5  per  cent.,  in  the  form  of  salve,  is  most  frequently  employed; 
it  is  to  be  jilaced  in  the  conjunctival  sac  once  or  twice  daily.  If, 
as  rarely  happens,  it  be  not  well  borne,  lukewarm  drops  of  a  weak 
solution  of  corrosive  sublimate  should  next  be  tried : 

R  Hydrarg.  chlurid.  corrosiv.,       0.06  =  about  gr.  i; 
Aqu^,  200.00=      "      5  vi. 

In  mild  cases,  in  which  it  is  wished  to  continue  the  treatment  a 
long  time,  in  order  to  guard  against  relapses  or  to  remove  all 
traces  of  the  disease,  calomel  is  a  very  useful  remedy.  It  is  used 
in  the  form  of  a  very  fine  powder,  and  is  dusted  into  the  eye  with 
a  dry  camel-hair  brush. 

Relapsing  jihlyctenular  conjunctivitis  depending  upon  scrofula 
demands  the  appropriate  general  treatment. 


DISEASES  OF  THE  CORNEA. 


The  recognition  of  corneal  diseases,  as  well  as  of  all  patho- 
logical products  in  the  anterior  chamber,  the  iris,  or  the  pupillary 
region,  is  greatly  facilitated  by  the  method  of  focal  illumination, 
the  introduction  of  which  into  ophthalmology  we  owe  to  Helm- 
holtz.*  It  consists,  essentially,  in  concentrating  the  flame  of  a 
lamp,  in  a  darkened  room,  by  means  of  a  convex  lens  of  about  2 
inches  focal  distance,  upon  the  point  which  is  the  special  object 
of  examination. 

This  point  is  thus  intensely  illuminated,  and  all  the  more  dis- 
tinctly from  the  fact  that  the  surrounding  tissues  He  in  the  shadow 
of  the  convex  lens. 

By  means  of  the  convex  lens  the  inverted  image  of  the  flame 
is  cast  upon  the  cornea,  and  moved  gradually  over  its  entire  sur- 
face. Then,  by  holding  the  lens  a  little  nearer  the  eye,  the  image 
of  the  flame  may  be  cast  upon  the  iris,  upon  the  anterior  capsule 
of  the  lens,  into  the  lens  itself,  and,  when  the  pupil  is  dilated, 
even  into  the  vitreous  body. 

If  it  be  desired  at  the  same  time  to  magnify  the  objects  under 
observation,  it  is  best  done  by  a  simple  binocular  lens,  such  a  one 
as,  having  an  opening  of  2^  to  3  inches  and  provided  with  a  suit- 
able handle,  is  used  by  old  people  as  a  reading  glass.  The  observer 
holds  the  glass  at  such  a  distance  as  allows  him  to  look  through  it 
with  both  eyes,  while  the  distance  to  the  object  examined  is  that 
at  which  it  is  most  magnified.  In  this  way  not  only  the  dimen- 
sions of  surface  but  those  of  depth  also  are  magnified,  and,  in  ex- 
amining corneal  diseases,  this  has  the  advantage  that  it  enables 
one  to  determine  whether  only  the  superficial  layers,  or  the  deeper 
ones  as  well,  are  aflected. 

The  diseases  of  the  cornea,  like  those  of  the  conjunctiva,  can 
be  divided  only  into  certain  great  groups,  but  even  then  it  by  no 

*  Arch.  f.  Oplith.,  B.  i.  2,  pag.  44. 

291 


292  ,  PHLYCTENULAR    KERATITIS. 

means  follows  that  every  case  as  it  occurs  in  practice  may  be 
referred  immediately  to  one  of  these  divisions. 

PHLYCTENULAR    KERATITIS. 

This  is  a  very  frequent  and  varied  form  of  disease.  It  is  char- 
acterized by  the  appearance  upon  some  part  of  th&  cornea  of  small, 
sharply  defined  centres  of  inflammation,  which,  when  they  first 
appear,  are  elevated  above  the  general  surface  of  the  cornea  in  the 
form  of  small  gray  prominences,  varying  from  the  size  of  a  poppy- 
seed  to  that  of  a  millet.  In  its  further  course  this  infiltration 
breaks  down,  leaving  a  loss  of  substance  whose  various  forms 
shall  be  described  later.  The  eruption,  and  frequently,  too,-  the 
further  course  of  phlyctenular  keratitis,  is  generally  accompanied 
by  severe  irritation. 

Eitlier  the  entire  margin  of  the  cornea  or  that  part  near  the 
centre  of  inflammation  is  surrounded  by  a  redness  due  to  the  in- 
jection of  the  thickly  crowded,  radiating,  episcleral  vessels.  The 
scleral  and  palpebral  conjunctiva  participate  more  or  less  in  the 
hyperemia.  It  is  often  inflamed  and  swollen,  and  yields  a  muco- 
purulent secretion. 

The  photophobia  which  is  caused  by  this  process  is  in  children 
often  so  great  that  they  cannot  be  induced  to  open  their  eyes,  but 
seek  the  darkest  corner  of  the  room  and  bury  their  faces  away 
from  the  light.  The  skin  is  drawn  into  a  fold  at  the  outer  angle 
of  the  eye,  in  consequence  of  the  spasmodic  closure  of  the  lids, 
and  is  excoriated  by  being  constantly  wet  with  tears.  An  exam- 
ination under  these  circumstances  is  often  very  difficult;  a  volun- 
tary opening  of  the  lids  cannot  be  obtained,  and  the  most  careful 
efforts  on  the  part  of  the  physician  to  open  them  excite  the  most 
violent  movements  of  the  head  and  of  the  entire  body.  In  these 
cases  it  is  therefore  necessary,  both  with  reference  to  the  prognosis 
and  treatment,  so  to  conduct  the  examination  that  its  results  may 
be  certain.  It  is  best  to  lay  small  children  upon  the  back  on  the 
lap  of  the  nurse,  who  at  the  same  time  holds  the  hands  while  the 
examiner  takes  the  head  of  the  child  between  his  knees,  and  then 
carefully  separates  the  lids,  without,  however,  everting  them. 

The  cornea  generally  at  first  rolls  upward,  but  generally,  too, 
after  a  few  moments,  turns  downward  again,  and  becomes  visible 
in  the  palpebral  fissure.     If  the  cornea,  however,  remain  hidden 


PHLYCTENULAR    KERATITIS.  293 

under  the  upper  lid,  the  eye  may  be  rolled  downward  with  the 
fixation  forceps.  The  examination  under  chloroform  .narcosis  is 
the  best  method,  and  very  slight  narcosis  answers  the  purpose. 

The  excessive  blepharospasm  which  accompanies  phlyctenular 
keratitis  depends  probably  upon  a  direct  irritation  of  the  corneal 
nerves.  Iw^anoflf*  found,  in  certain  of  these  cases  of  keratitis,  an 
accumulation  of  cells  between  the  epithelium  and  Bowman's  mem- 
brane; the  epithelium  covering  the  phlyctenule  was  quite  normal, 
and  but  slightly  raised ;  the  corneal  tissue  below  showed  no 
chancres,  and  in  certain  cross  sections  the  communication  between 
the  phlyctenule  and  the  corneal  tissue  could  be  detected.  Within 
the  corneal  substance  the  cellular  infiltration  was  more  or  less 
crowded  along  the  course  of  the  fine  nerves,  surrounding  them  as 
they  jienetrated  Bowman's  membrane,  and  then  collecting  in  little 
heaps  beneath  the  elevated  epithelium. 

Aside  from  the  typical  phlyctenular  corneal  infiltration,  there 
are  still  to  be  mentioned,  as  special  forms  of  this  disease,  the 
marginal  keratitis,  and  the  so-called  fascicular  keratitis. 

The  phlyctenular  marginal  keratitis  begins  with  a  partial  or 
total  hyperemia  of  the  limbus  conjunctiva?  corneas;  it  appears 
thickened  and  covered  by  a  row  of  closely  crowded  little  promi- 
nences. The  process  may  go  no  farther,  or,  if  it  last  some  time, 
mav  invade  the  surface  of  the  cornea  proper.  The  neighboring 
marginal  part  of  the  cornea  appears,  then,  diffusely  clouded,  un- 
even, and  often  strewed  with  numerous  small  phlyctenules.  Later, 
fine  blood-vessels  run  across  the  limbus  conjunctiva  corneas. 

The  fascicular  keratitis  generally  develops  from  a  phlyctenular 
marginal  infiltration,  which  gradually  advances  toward  the  centre 
of  the  cornea,  the  thickly  crowded  blood-vessels  following  it  in  a 
ribbon-like  stripe.  At  first  this  infiltration  advances  quite  regu- 
larly, by  lines  radiating  toward  the  centre  of  the  cornea,  but  after 
having  passed  the  centre  it  often  bends  about  like  a  horseshoe. 
Finally  the  process  ceases,  leaving  behind  a  ribbon-shaped  cica- 
tricial stripe. 

More  rarely  it  happens  that,  instead  of  an  infiltration,  a  moder- 
ately deep  ulcer,  with  a  purulent  surface  and  followed  by  a  broad 
bundle  of  vessels,  creeps  from  the  margin  of  the  cornea  toward 

*  Klin.  Monatsbl.  f.  Augenheil.k.,  1869,  pag.  462. 


294  PHLYCTENULAR    KERATITIS. 

its  centre.  The  opacities  remaining  after  this  process  are  still 
greater. 

Phlyctenular  keratitis  stands  in  very  close  etiological  relation 
with  scrofula.  Corneal  diseases  in  general,  but  this  one  in  partic- 
ular, are  not  only  much  more  frequent  in  scrofulous  individuals, 
but  are  also  more  obstinate  and  dangerous  than  in  healthy  consti- 
tutions. 

Not  only  do  the  reflex  symptoms,  photophobia,  etc.,  occur  in 
scrofulous  children  in  their  most  intense  form  and  accompanying 
very  slight  objective  changes,  but  the  course  of  the  disease  is, 
under  these  circumstances,  slower  and  more  obstinate,  more  severe 
forms  occur,  and  relapses  are  more  frequent. 

The  recurring  inflammations,  moreover,  do  not  always  have 
their  seat  in  the  hitherto  intact  portions  of  the  cornea.  Frequently 
new  inflammation,  softening,  infiltration,  and  vascularization  occur 
in  old  scars  which  have  remained  from  former  inflammations. 

In  many  cases  the  cornea  becomes  very  vascular.  Its  whole 
surface  is  thus  covered  with  a  net-work ;  it  appears  uneven  in 
consequence  of  loss  of  epithelium,  and  looks  as  if  stippled.  In 
the  diffusely  clouded  corneal  substance  can  be  seen  a  number  of 
small  flakes,  which  are  partly  scar  tissue  and  partly  fresh  infil- 
tration. 

This  condition  of  cloudiness  and  vascularization  of  the  cornea, 
which  occurs  in  just  the  same  way  as  with  trachoma,  is  called 
pannus.  Formerly,  according  to  the  degree  of  the  opacity  a  dis- 
tinction was  made  between  a  pannus  crassus  sive  carnosus  and  a 
pannus  tenuis ;  but  this  distinction  rests  only  on  a  quantitative 
difference,  and  during  the  course  of  the  disease  the  one  form  may 
pass  into  the  other.  More  important,  because  resting  on  etiological 
grounds,  is  the  distinction  between  pannus  trachomatosus  and 
pannus  phlyctsenulosus,  but  in  this  connection  it  is  to  be  mentioned 
that  superficial,  pannous  keratitis  may  develop  without  any  ])re- 
ceding  keratitis  phlycttenulosa,  and  independent  of  conjunctival 
disease. 

The  course  varies  greatly.  In  favorable  cases  the  corneal 
phlyctenule  breaks  down,  leaving  a  small  superficial  loss  of  sub- 
stance, which  is  replaced  by  new  tissue.  The  traces  of  the  disease 
can  then  generally  be  detected  only  by  focal  illumination.  In 
other  cases  the  loss  of  substance  is  somewhat  greater,  its  margins 


PHLYCTENULAR    KERATITIS.  295 

flatten  down,  the  ulcer  becomes  clean  and  smooth,  and  is  finally 
covered  with  new  epithelium;  in  these  cases,  too,  a  slight  clouding 
of  the  tissues  is  to  be  observed  only  by  focal  illumination.  These 
so-called  corneal  facets  represent  a  peculiar  reparative  process, 
which  may  occur  in  the  same  way  in  other  corneal  diseases. 

Finally,  it  may  happen  that  the  loss  of  substance  assumes  the 
character  of  a  corneal  ulcer.  There  frequently  follows,  then,  a 
vascularization  of  the  ulcer  from  the  margin  of  the  cornea,  which 
facilitates  its  healing,  but  which  generally  disappears  very  slowly 
after  cicatrization. 

A  rather  rare  but  very  dangerous  complication  of  the  superficial 
phlyctenular  process  is  the  development  of  a  gray  or  gray-yellow 
infiltration,  which  appears  first  in  the  deep  layers  of  the  cornea, 
and  which  shows  a  decided  tendency  to  go  on  to  suppuration, 
formation  of  hypopion,  and  ulceration  of  the  cornea.  The  condi- 
tion in  fact  is  that  of  a  complication  by  hypopion-keratitis,  gen- 
erally with  great  irritation. 

Quite  as  rare  is  another  form  of  infiltration,  not  inclined  to 
suppuration,  but  involving  a  considerable  extent  and  depth  of 
the  corneal  tissue,  and  resembling  keratitis  parenchymatosa,  but 
differing  from  it  by  running  a  decidedly  more  rapid  course. 

With  unfavorable  hygienic  surroundings,  or  in  scrofulous  in- 
dividuals, phlyctenular  keratitis  may  persist  with  the  greatest 
obstinacy,  and  may  recur  so  often  as  greatly  to  endanger  vision 
by  the  opacities  which  it  leaves  behind. 

Treatment. — On  account  of  the  close  connection  between  scrofula 
and  phlyctenular  keratitis,  constitutional  treatment  is  in  manv  of 
these  cases  very  essential.  Preparations  of  iron,  salt-baths,  etc., 
are  frequently  employed.  But  aside  from  the  fact  that  circum- 
stances generally  make  it  impossible  to  regulate  the  hygienic  sur- 
roundings, the  results  to  be  expected  from  anti-scrofulous  treatment 
are  so  tardy  that  they  cannot  be  relied  on  to  avert  the  pressing 
danger  always  threatened  by  diseases  of  the  cornea.  The  most 
reliance  must  be  placed  upon  the  local  treatment.  The  first  indi- 
cation is  to  allay  the  irritability.  This  is  generally  best  done  at 
first  by  cold-water  or  lead-water  dressings  and  atropine.  The 
atropine  must  from  the  first  be  so  employed  that  a  sufficient  mv- 
driasis  is  caused  and  maintained,  a  thing  difficult  to  do  on  account 
of  the  irritability.     Frequently  the  action  of  the  atropine  proves 


296  PHLYCTENULAR    KERATITIS. 

insufficient  and  very  transitory.  In  the  later  stages  of  tlie  dis- 
ease, where  the  irritability  has  lasted  a  long  time,  lukewarm 
applications  are  better  than  cold.  When  the  irritability  is  lessened, 
the  local  use  of  mercurials  is  indicated  just  as  in  phlyctenular 
conjunctivitis.  The  principal  remedies  used  are  the  yellow  oxide 
of  mercury,  1  or  2  per  cent.,  in  salve  form,  and  calomel,  which  is 
dusted  into  the  eye  as  a  fine  powder.  If  these  remedies  do  not 
prove  useful,  pencilling  with  a  1  or  2  per  cent,  solution  of  nitrate 
of  silver  often  causes  rapid  improvement.  This  treatment  is  par- 
ticularly indicated  in  those  cases  in  which  the  disease  has  lasted 
a  long  time,  and  hypersemia  and  swelling  of  the  conjunctiva 
have  developed.  Under  such  circumstances  mercurials  generally 
prove  more  or  less  inefficacious,  while  the  best  results  are  obtained 
by  the  local  treatment  of  the  conjunctiva,  particularly  in  the 
superior  fornix. 

Mercurials  are  also  not  generally  well  borne  Avhen  the  disease 
is  complicated  by  the  above  described  purulent  inflammation  of 
the  deeper  layers,  and  still  on  account  of  the  dangerous  nature  of 
this  complication  some  promptly  acting  treatment  is  necessary. 
It  seems  best  in  these  cases  to  use  atropine  liberally,  and  warm 
fomentations,  alternating  with  a  pressure-bandage.  If  this  do 
not  ])rove  sufficient,  chlorine  water  or  a  1  per  cent,  solution  of  the 
muriate  of  quinia  may  be  dropped  into  the  eye  three  or  four  times 
during  the  day. 

The  deep  infiltration  resembling  keratitis  parenchymatosa  gener- 
ally disappears  rapidly  under  the  use  of  atropine  and  the  pressure- 
bandage. 

The  treatment  above  described  is  also  suitable  for  pannus  phlyc- 
tcenulosus.  The  improvement  of  the  general  health  is  often  very 
important.  The  fresh  country  air  often  exercises  a  surprisingly 
good  influence.  Among  the  local  remedies  are  calomel,  red  precipi- 
tate salve,  and  lukewarm  washes  of  corrosive  sublimate  (solution, 
1  part  to  3000  or  4000).  Swelling  of  the  conjunctiva,  especially  at 
the  fornix,  demands  generally  the  use  of  nitrate  of  silver.  Chlorine 
water  may  also  often  be  used  to  adv^antage.  Under  this  treatment 
the  vascularization  may  disappear  entirely,  and  the  cornea  again 
become  so  clear  that  by  ordinary  daylight  no  abnormity  can  be 
seen  in  it.  But  nevertheless  there  remains  over  the  whole  surface 
a  delicate  clouding,  visible  by  focal  illumination. 


PARENCHYMATOUS    KERATITIS.  297 

For  very  obstinate  cases  of  pannus  the  operation  of  iieriotoniy 
or  synclectomy  is  recommended.  It  consists  in  the  removal  of  a 
circular  strip,  3  to  5  mm.  wide,  from  about  the  cornea.  In  the 
course  of  a  few  months  the  cornea  becomes  surrounded  by  a  ring 
of  dense  cicatricial  tissue,  which  cuts  off  the  blood-supply  from  the 
vessels  ramifying  on  it. 

Obstinate  and  relapsing  cases  are  frequently  checked  by  a  deriv- 
ative treatment.  The  practice  so  often  resorted  to  by  the  English 
ophthalmologists,  of  inserting  in  the  temple  a  small  seton  consist- 
ing of  4  or  5  cotton  threads,  is  a  good  one. 

PARENCHYMATOUS    KERATITIS. 

Keratitis  profunda,  interstitialis,  or  parenchymatosa,  is  a  very 
well  defined  form  of  disease  which  in  the  majority  of  cases  is 
bilateral.  As  a  rule,  both  eyes  are  not  attacked  at  the  same  time, 
but  first  one  and  then,  after  an  interval  of  some  weeks  or  months, 
the  other.  There  is  often,  therefore,  the  opportunity  to  observe  the 
development  of  the  disease  in  the  second  eye.  After  an  increased 
irritability  has  been  observed  for  some  time  in  the  eye,  a  bright- 
red  injection  of  the  eptiscleral  vessels  appears  in  the  neighborhood 
of  the  ciliary  body;  this  gradually  approaches  the  margin  of  the 
cornea,  and  there  attains  its  greatest  intensity.  Simultaneously 
appears  a  clouding  of  the  corneal  substance,  which  begins  either 
in  the  centre  of  the  cornea,  and  from  there  spreads  out  in  the  course 
of  a  few  days  or  Aveeks  toward  the  periphery,  where  it  often  leaves 
a  small  marginal  part  of  the  cornea  free,  or  beginning  at  any  point 
of  the  margin,  it  spreads  from  there  over  the  entire  cornea. 

At  first  the  cornea  appears  semi-transparent,  somewhat  like 
ground  glass.  Later,  bright  gray  or  gray-yellow  indistinctly 
defined  spots  appear,  mostly  near  the  centre  of  the  cornea,  often 
uniting  together  to  form  an  annular  figure.  These  opacities  lie 
in  the  deep  layers  of  the  cornea,  while  the  surface,  when  examined 
through  a  convex  lens  and  by  focal  illumination,  appears  uneven. 

At  first  there  is  no  vascularization  of  the  cornea,  and  as  a  gen- 
eral thing  mild  cases  of  keratitis  profunda  run  their  course  with- 
out the  development  of  blood-vessels  in  the  cornea.  Frequently 
a  fine  vascular  net  with  large  meshes  appears  upon  the  surface  of 
the  cornea,  just  as  in  other  forms  of  keratitis.  There  is,  however, 
a  certain  kind  of  vascularization  which  is  especially  characteristic 

20 


298  PARENCHYMATOUS    KERATITIS. 

of  this  form.  The  entire  margin  of  the  cornea  is  encroached 
ujDon  by  closely  crowded,  short  vessels  radiating  toward  the  centre. 
Without  advancing  any  farther  they  may  remain  a  long  time 
stationary.  But  in  the  worst  cases  these  vessels  creep  steadily 
on  toward  the  centre  of  the  cornea.  The  opacity  of  the  cornea 
becomes  so  great  that  it  assumes  a  dirty-red  flesh  color,  while  its 
middle,  so  long  as  it  is  not  vascularized,  is  by  its  bright  gray  color 
sharply  defined  from  the  surrounding  vascularized  part. 

Gradually  the  vessels  reach  the  middle  of  the  corneal  surface, 
and  not  till  then  does  the  retrogressive  process  begin  in  the  vas- 
cularization. By  this  process  the  cornea  becomes  clearer.  This 
affection  does  not  cause  ulcerations  of  the  cornea. 

Even  in  a  few  weeks  after  the  ai)pearance  of  the  disease  the 
cornea  may  become  so  opaque  that  the  condition  of  the  iris  can- 
not be  accurately  observed.  Generally  Avhen  the  cornea  clears  up 
again,  the  iris  is  found  unchanged  and  acting  normally,  but  some- 
times the  existence  of  adhesions  shows  that  there  has  been  iritis. 

The  subjective  symptoms  vary  in  intensity.  In  mild  cases,  in 
which  there  is  no  vascularization  of  the  cornea,  and  where  the 
development  of  vessels  about  its  margin  is  only  slight,  the  patients 
generally  complain  only  of  indistinctness  of  vision  and  an  inclina- 
tion of  the  eyes  to  redness  and  weeping.  Where  there  is  greater 
opacity  and  vascularization  there  is  more  irritability,  photophobia, 
lachrymation,  pain,  etc. 

The  course  of  the  disease  is  ahvays  slow,  extending  over  several 
months.  As  a  rule,  vision,  after  recovery,  is  more  or  less  injured 
according  to  the  severity  of  the  case.  There  remain  diffuse  or 
punctated  opacities,  frequently  to  be  seen  only  by  focal  illumina- 
tion. Still,  the  final  result  is  generally  more  favorable  than  one 
would  expect  from  the  appearance  of  the  disease  at  its  height. 

The  causes  are  frequently  of  a  constitutional  nature ;  at  least 
the  circumstance  that  it  generally  affects  both  eyes  would  so  indi- 
cate. It  occurs  most  frequently  in  children  and  young  persons 
whose  health  and  general  nutrition  are  bad ;  but  quite  healthy  per- 
sons with  good  hygienic  surroundings  are  sometimes  attacked. 
Hutchinson's*  view,  that  this  form  of  keratitis  is  to  be  regarded 
as  the  direct  consequence  of   congenital  syphilis,  has  not  been 

*  Ophth.  Hosp.  Kep.,  1858,  No.  5,  pag.  229. 


PUNCTATED    KEEATITIS.  299 

generally  accepted  in  Germany.  The  disease  undoubtedly  occurs 
in  individuals  absolutely  fi'ee  from  syphilis. 

Hutchinson  refers  to  a  certain  abnormal  development  of  the 
teeth  as  nearly  constantly  associated  with  the  disease,  but  this,  too, 
is  absent  in  many  cases.  The  peculiarity  of  this  abnormity  is  that 
the  middle  of  the  cutting  edge  of  the  incisors,  which  sliould  be 
the  most  prominent  part,  crumbles  down  and  assumes,  especially 
in  the  two  upper  front  teeth,  a  concave  form. 

Keratitis  parenchymatosa  is  most  frequent  from  the  sixth  to 
the  twentieth  year.  After  that  it  is  rarer,  and  its  course,  when  it 
occurs,  is  milder. 

In  making  the  prognosis,  we  have  to  consider  the  length  of  the 
process  and  the  remaining  opacities.  These  last  are  generally  so 
much  the  greater  the  higher  the  inflammation  and  the  more  ex- 
tensive the  vascularization  of  the  cornea  has  been. 

Tlie  treatment  of  this  form  of  keratitis  cannot  be  a  very  active 
one.  Improvement  of  the  hygienic  surroundings,  attention  to 
constitutional  disturbances,  protection  of  the  eyes  from  injurious 
influences  of  all  kinds,  and  patience  on  the  part  of  the  physician 
and  patient,  are  the  principal  points  in  the  therapeutic  pro- 
gramme. Iodide  of  potassium  and  preparations  of  iron  are  gen- 
erally to  be  recommended.  The  local  treatment  should  be  such 
as  to  diminish  as  much  as  possible  the  irritability.  For  this  pur- 
pose warm  fomentations  and  atropine  are  best.  All  irritants  are 
to  be  avoided.  Hasner*  recommends  the  paracentesis  of  the  cor- 
nea for  all  cases  which  are  free  from  complications,  and  in  Mhich 
the  cornea,  although  considerably  clouded,  is  but  little  or  not  at 
all  vascularized,  while  the  hypersemia  of  the  sclera  and  the  ciliary 
neuralgia  are  but  slight.  It  is  especially  in  recent  cases  of  this 
kind,  in  which  the  affection  has  lasted  but  a  few  weeks,  that 
favorable  results  have  been  observed  to  follow  paracentesis. 

Keratitis  punctata  is  a  quite  rare  atfection,  and  one  always  com- 
plicated with  iritis;  it  ought  not,  however,  for  that  reason  to  be 
confounded  with  certain  cases  of  iritis,  which  are  characterized  bv 
a  precipitate  upon  the  membrane  of  Descemet.  With  inflamma- 
tory symptoms,  and  the  corresponding  irritability,  there  develop 
in  the  parenchyma  of  the  cornea,  isolated,  circumscribed,  white 


*  Klinische  Yortrage  iiber  Augenheilkunde,  pag.  163. 


300  PURULENT    KEEATITIS. 

specks  about  the  size  of  a  hemp-seed,  and  surrounded  by  a  diffuse 
cloudins;.  After  a  few  davs  the  adhesion  of  the  niaro-in  of  the 
pupil  with  the  capsule  of  the  lens,  shows  the  existence  of  iritis. 
As  the  process  advances,  these  specks  multiply;  they  run  together 
at  places,  forming  irregular  lines,  the  diffuse  clouding  becomes 
denser,  and  the  adhesions  of  the  iris  more  numerous. 

The  disease  is  most  frequent  in  children  before  the  time  of 
puberty,  and  aj)pears  frequently  to  be  of  a  syphilitic  nature.  It 
is  not  near  so  frequent  as  keratitis  profunda,  runs  a  less  typical 
course,  and  appears,  at  least  at  first,  to  be  more  amenable  to  treat- 
ment. Continued  and  extreme  mydriasis,  by  the  use  of  sulphate 
of  atropia,  is  indicated,  and  so  is  iodide  of  potassium  in  cases 
which  are  suspected  to  be  caused  by  sy]>hilis  or  scrofula.  Some 
cases  which  I  have  been  able  to  treat  from  the  first  in  this  man- 
ner, I  have  seen  heal,  leaving  only  small  perijiheral  spots  in  the 
cornea  and  with  vision  unimpaired,  while,  if  the  disease  be  neg- 
lected,— as  it  is  very  apt  to  be,  as  its  symptoms  are  at  first  not 
severe, — the  corneal  opacities  become  more  numerous  and  denser, 
and  interfere  greatly  with  vision,  while  simultaneously  the  danger 
from  the  persistence  of  the  iritis  is  very  great. 

Aside  from  atropine  and  the  continued  use  of  derivatives  and 
attention  to  existing  constitutional  anomalies,  the  question  of  iri- 
dectomy may  often  arise,  partly  for  optical  reasons,  partly  to  check 
the  progress  and  avoid  the  ruinous  consequences  of  chronic  iritis. 

PURULENT    KERATITLS. 

A  purulent  process  in  the  cornea  may  occur  as  a  symptom  of 
very  different  diseases.  In  the  strictest  sense,  however,  by  puru- 
lent keratitis  are  understood  those  cases  which  occur  as  an  inde- 
pendent disease.  If  the  case  be  one  in  which  there  is  a  circum- 
scribed collection  of  pus  in  the  tissue  of  the  cornea,  it  is  generally 
called  a  corneal  abscess.*  Since  in  many  cases  of  purulent  kera- 
titis there  is  at  the  same  time  a  collection  of  pus  in  the  anterior 

*  A  corneal  abscess  was  generally  designated  by  the  term  Onyx  or  Unguis 
by  the  older  ophthalmological  writers.  Jiingken  discriminated  between  ab- 
scessus  corneiB  and  onyx,  meaning  by  the  latter  a  congestion  abscess, — that  is, 
a  collection  of  pus  in  the  tissue  of  the  cornea  at  its  lower  margin,  formed  by 
the  sinking  of  the  pus  from  an  abscess,  ulcer,  or  wound  in  the  upper  part  of 
the  cornea. 


PURULENT    KERATITIS.  301 

chamber,  Roser*  has  proposed  for  this  condition  the  very  suitable 
name  of  "hypopion  keratitis." 

The  beginning  of  tliis  affection  is  always  near  the  centre  and  in 
the  deeper  layers  of  the  cornea.  At  that  place  there  appears  a 
round,  circumscribed,  gray  opacity,  in  which,  when  examined  with 
a  magnifying  lens  and  by  focal  illumination,  a  number  of  short 
gray  strise  may  be  detected.  They  may  be  either  parallel  with 
one  another  or  radiating.  The  superficial  layers  of  the  cornea 
are  at  the  same  time  diffusely  clouded,  and  there  are  many  small 
defects  and  irregularities  in  the  epithelial  covering. 

The  infiltration  of  the  deeper  layers  now  assumes  gradually  a 
yellowish  purulent  color,  while  a  loss  of  substance  occurs  upon 
the  surface.  The  appearance  of  these  superficial  ulcers  is  very 
varied.  Often  the  ulcer  is  no  larger  than  the  purulent  infiltration, 
has  the  appearance  of  a  so-called  corneal  facet,  with  a  smooth,  glis- 
tening floor,  clean  margins,  and  no  steep  walls,  exactly  as  if  a  piece 
had  been  sliced  from  the  cornea  by  a  single  cut  with  a  sharp  knife. 
It  is  very  easy  to  conceive,  under  these  circumstances,  that  by  the 
collapse  of  an  abscess  the  anterior  surface  of  the  cornea  has  sunk 
in.  The  possibility  of  such  a  process,  as  described  by  Arlt,t  can- 
not be  questioned,  but,  as  a  general  rule,  this  change  of  form  seems 
to  be  due  to  a  superficial  disintegration  of  tissue. 

In  other  cases  the  superficial  ulcer  attains  soon  a  greater  size 
than  the  purulent  infiltration  behind  it;  its  margins  are  sometimes 
flat,  sometimes  steep,  and  are  often  quite  clean,  that  is,  free  from 
any  purulent  infiltration ;  it  is  then  sometimes  not  easy  to  recognize 
the  full  extent  of  the  loss  of  substance. 

Frequently  there  is  some  punctated  purulent  infiltration  in  the 
corneal  substance  surrounding  the  margin  of  the  ulcer. 

The  further  course  and  the  entire  type  of  the  disease  depend 
essentially  upon  whether  the  deep  purulent  infiltration  or  the 
superficial  ulcer  becomes  more  extensive.  Cases  of  the  first  kind 
are  called  corneal  abscesses,  on  account  of  the  circumscribed  accu- 
mulation of  pus  in  the  tissue  of  the  cornea.  Unless  recovery  is 
rapid,  the  enlargement  of  the  abscess  and  of  the  superficial  ulcer 
causes  extensive  destruction  of  tissue. 

Other  cases  assume  a  dangerous  character,  less  from  the  jjuru- 

*  Arch.  f.  Ophth.,  B.ii.  2,  pag.  151.  f  Ibid.,  B.  xvi.  1. 


302  PURULENT    KERATITIS. 

lent  process  in  the  deeper  parts  of -the  cornea  than  from  the  puru- 
lent infiltration  of  the  edges  of  the  ulcer.  The  floor  of  the  ulcer 
is  often  also  purulently  infiltrated,  and  this  is  especially  true  of 
small  ulcers ;  or  it  may  be  quite  clean  and  smooth ;  or  finally,  by 
the  help  of  focal  illumination  and  a  magnifying  lens,  it  may  be 
seen  to  be  gray  and  clouded,  and  to  contain  numerous  gray-white, 
punctated,  purulent  infiltrations.  This  purulent  infiltration  of  the 
margin  of  the  ulcer  is  generally  only  at  one  part  of  its  circum- 
ference, and  shows  itself  in  the  form  of  a  dirty,  yellowish-white 
line,  while  the  remaining  part  of  the  circumference  is  clean  and 
smooth,  and  therefore  more  difficult  to  see.  The  ulcer  spreads 
toward  the  side  of  the  infiltrated  margin,  and  after  a  time  comes 
to  a  stand-still  at  this  point,  but  the  process  is  renewed  at  some 
other  portion  of  the  circumference,  and  the  tissue  in  its  neighbor- 
hood is  destroyed. 

Since  this  destructive  process  gradually  creeps  over  the  surface 
of  the  cornea,  Siimisch*  has  designated  this  form  of  disease  as 
ulcus  corner  serpens.  These  ulcers  frequently  appear  flatter  than 
they  really  are,  since  the  thinned  floor  yields  to  the  pressure  of 
the  aqueous  humor  and  is  pressed  forward.  Between  the  corneal 
abscess  and  the  ulcus  serpens  there  are  many  intermediate  forms. 

In  the  great  majority  of  cases  of  purulent  keratitis  pus  collects 
in  the  anterior  chamber.  In  such  cases  iritis  "generally  exists  at 
the  same  time;  but  cases  do  undoubtedly  occur  in  which  hypopion 
exists,  while  the  iris  still  reacts  promptly  under  atropine  and  there 
are  no  adhesions  with  the  capsule,  nor  any  other  traces  of  inflam- 
mation. 

The  belief  formerly  generally  accepted,  that  the  hypopion  was 
due  to  a  participation  in  the  purulent  process  by  the  epithelium  of 
the  membrane  of  Descemet,  seems  no  longer  plausible,  since  we 
have  come  to  regard  the  pus-cells  as  identical  with  the  white  blood- 
corpuscles.  The  ])rocess  of  a  direct  rupture  of  the  abscess  into 
the  anterior  chamber,  as  described  by  A.  Weber,t  I  have  never 
been  able  satisfactorily  to  observe.  But  one  very  often  sees  a 
yellowMsli-white  thread  of  pus,  of  greater  or  less  thickness,  lying 
close  to  the  membrane  of  Descemet,  and  extending  from  the  ulcer 

*  Das  ulcus  corneae  serpens,  Bonn,  1870. 
t  Arch.  f.  Ophth.,  B.  viii.  1,  pag.  322. 


PURULENT    KERATITIS.  303 

down  to  the  lower  margin  of  the  cornea.  But  upon  examination 
with  focal  illumination,  it  is  irajjossible  to  say  whether  it  lies  be- 
fore or  behind  the  membrane.  The  structure  of  the  deeper  layers 
of  the  cornea  is  so  loose,  and  their  connection  with  the  membrane 
of  Descemet  is  so  slight,  that  the  wandering  downward  of  the  pus- 
cells,  assisted  by  gravity,  meets  with  but  little  obstruction.  But 
when  the  pus  has  once  reached  the  membrane  of  Descemet,  it  can 
easily  pass  through  the  openings  of  the  ligamentum  pectinatura 
into  the  anterior  chamber.  It  is  possible  that  the  pus  may  settle 
in  this  manner,  but  the  question  is,  does  it  actually  do  so?  Ac- 
cording to  Horner's*  observations,  this  process  takes  place  on  the 
posterior  surface  of  the  membrane  of  Descemet.  The  pus-cells 
from  the  corneal  ulcer  penetrate  the  membrane  of  Descemet, 
accumulate  upon  its  posterior  surface,  and  finally  sink  downward. 
Evidently  an  accumulation  of  pus  in  the  corneal  substance  could 
not  immediately  rise  and  discharge  itself  with  the  aqueous  humor 
when  a  puncture  is  made  in  the  cornea  at  some  distance  from  it 
in  the  horizontal  direction.  At  least  the  walls  of  the  channels 
through  which  it  had  sunk  would  remain  infiltrated  and  would 
show  a  distinct  cloudiness.  If  now,  after  paracentesis  of  the 
cornea,  nothing  remain  but  the  diffuse  clouding  of  the  anterior 
layers,  we  are  forced  to  the  conclusion  that  the  appearances  which 
seemed  to  be  in  the  corneal  substance,  really  were  in  the  anterior 
chamber.  Experiments  upon  the  eyes  of  guinea-pigs  and  rabbits 
have  furnished  results  which  confirm  this  view. 

Iritis  is  a  complication  which  generally  occurs  quite  ejirly  and 
is  seldom  absent.  The  change  in  the  color  of  the  iris,  caused  by 
it,  cannot  always  be  well  seen,  on  account  of  the  clouding  of  the 
cornea,  but  can  generally  be  detected,  at  least  at  the  margin  of 
the  pupil.  The  diagnosis  is  confirmed  by  the  posterior  synechiae, 
which  are  made  to  appear  by  the  action  of  atropine.  Often  there 
are,  simultaneously,  especially  near  the  lower  margin  of  the  pupil, 
serai-transparent  flakes  floating  in  the  aqueous  humor,  which  pre- 
sent exactly  the  appearance  of  coagulated  fibrin.  Frequently,  in 
consequence  of  the  purulent  infiltration,  the  tissue  of  the  iris,  as 
appears  in  the  operation  of  iridectomy,  is  exceedingly  weak  and 
brittle. 

*  Comp.  Marie  Biikowa,  Inaugural-Dissertation,  Zurich,  1871. 


304  PUEULENT    KERATITIS. 

The  conjunctiva,  especially  on  the  sclera,  is  strongly  injected 
and  often  swollen.  Pain,  lachryniation,  etc.,  are  sometimes  slight 
and  sometimes  severe. 

The  causes  of  purulent  keratitis  are  in  the  majority  of  cases 
traumatic.  It  is  often  caused  by  slight  contusions  and  wounds 
of  the  cornea  by  little  pieces  of  stone  or  other  splinters,  and  in 
country-people  most  frequently  by  wounds  from  the  beards  of 
grain  during  harvest.  Neglect  is  often  the  reason  why  such 
slight  injuries  assume  so  dangerous  a  character;  still,  an  indi- 
vidual predisposition,  which  causes  such  insignificant  wounds  to 
run  so  unfavorable  a  course,  cannot  be  denied.  Generally,  the 
cases  are  in  poorly-nourished,  hard-working  individuals. 

Colds  are  considered  also  as  causing  purulent  keratitis.  In 
many  cases  no  determinate  cause  can  be  ascertained. 

Amonsr  the  non-traumatic  cases  should  be  mentioned  the  non- 
irritating  form  of  corneal  infiltration  described  by  Von  Graefe.* 
It  occurs  in  children  under  eight  years  of  age,  and  presents  the 
pure  type  of  a  corneal  abscess  with  remarkably  slight  subjective 
symptoms. 

The  course  is  very  tedious  and  without  any  tendency  to  spon- 
taneous healing.  Left  to  itself,  the  ulceration  spreads  over  the 
entire  cornea,  ending  generally  rather  late  in  perforation,  which 
is  followed  by  prolapse  of  the  iris,  development  of  staphyloma, 
etc.  The  already  existing  purulent  iritis  favors  a  transition  into 
choroiditis  and  ultimate  atrophy  of  the  eye. 

Treatment. — Atropine,  lukewarm  fomentations,  and  the  press- 
ure-bandage are  generally  the  means  first  resorted  to,  and  in  mild 
cases  are  sufficient.  In  the  first  place  the  hypopion  generally  dis- 
appears, and  gradually  also  the  purulent  infiltration  in  the  cornea. 
The  ulcer  becomes  clean,  and  heals,  leaving  a  superficial  opacity. 
If  the  clearing-up  of  the  ulcer  be  delayed,  a  drop  of  chlorine  waterf 
three  or  four  times  daily,  in  the  eye,  is  to  be  recommended.  I 
have  also  seen  good  results  follow  the  use  of  a  1  or  2  per  cent, 
solution  of  the  muriate  of  quinia.  Dilute  tincture  of  opium  is 
also  recommended  under  these  circumstances. 

If  there  be  great  irritability,  subcutaneous  injections  of  nior- 

*  Arch.  f.  Ophth.,  B.  vi.  2,  pag.  135. 
t  Ibid.,  B.  X.  2,  pag.  204. 


I 


PURULENT    KERATITIS.  305 

pliine  are  to  be  made  in  the  temporal  or  supraorbital  region,  and 
in  every  case,  quiet  sleep  is  to  be  secured  by  morphine  or  chloral, 
if  necessary. 

In  many  cases  an  improvement  occurs  at  first,  the  hypo])ion 
diminishes,  but  soon  without  any  apparent  cause  the  purulent 
infiltration  begins  to  increase,  and  the  hypopion  becomes  larger. 
If  these  relapses  gradually  make  the  condition  worse;  if  in  spite 
of  suitable  treatment  the  hypopion  increase  and  the  corneal  ulcer 
spread,  the  reason  generally  is  that  the  iritis,  which  is  very  apt 
to  assume  a  purulent  character,  has  gained  the  upper  hand.  Atro- 
pine is  then  insufficient  to  meet  the  case,  the  pressure-bandage  is 
no  longer  well  borne,  and  all  irritants,  such  as  chlorine  water, 
tincture  of  opium,  etc.,  seem  to  be  actually  hurtful.  The  discharge 
of  the  hypopion  by  puncture  of  the  cornea  is  often  resorted  to  in 
these  cases,  but  is  not  always  sufficient.  Frequently  on  account 
of  its  viscidity  the  hypopion  cannot  escape  from  a  small  corneal 
wound,  but  even  if  entirely  discharged  through  a  larger  wound, 
it  often  soon  collects  again,  since  the  corneal  suppuration  and  the 
iritis  continue.  In  many  cases,  escape  from  this  dilemma  is  oifered 
by  iridectomy,  as  proposed  by  Von  Graefe.*  The  wound  for  this 
purpose  is  best  made  with  a  small  cataract  knife,  in  the  periphery 
of  the  upper  corneal  margin,  and  should  be  large.  The  operation 
promises  no  optical  advantages,  in  view  of  the  later  cicatrization 
of  the  ulcer,  since  on  account  of  the  severe  iritis  the  coloboma  of 
the  iris  always  closes  again.  Iridectomy  is  often  of  decided  nse, 
and  checks  malignant  cases  which  would  yield  to  no  other  treat- 
ment. Its  effect  is  uncertain  when  it  is  resorted  to  at  too  late  a 
period  of  the  disease,  after  more  than  half  the  cornea  is  destroyed. 
Frequently,  too,  iridectomy  cannot  well  be  performed,  because  the 
iris  is  so  rotten  that  it  crumbles  when  grasped  with  the  forceps. 

The  artificial  opening  of  the  corneal  abscess  is  not  absolutely 
reliable.  Authorities  have  been  much  divided  as  to  the  results 
of  this  practice.  Mackenzief  asserts  emphatically  that  he  has 
always  seen  it  followed  by  extensive  destruction  of  the  cornea, 
with  subsequent  partial  or  total  staphyloma;  while  other  authors 
regard  the  incision  of  the  anterior  abscess  wall,  or  even  the  entire 

*Arch.  f.  Ophtb.,  B.  ii.,  pag.  241  ;  B.  vi.  2,  pag.  139;  B.  x.  2,  pag.  205. 
f  Practical  Treatise,  etc.,  London,  1854,  pag.  627. 


306  NEURO-PARALYTIC    KERATITIS. 

thickness  of  the  cornea  throughout  the  whole  extent  of  the  abscess, 
as  advisable. 

In  ulcus  cornete  serpens,  also,  Siimisch  recommends  the  splitting 
as  early  as  possible  of  the  floor  of  the  ulcer  over  its  whole  breadth, 
and  even  the  extending  of  the  incision  beyond  the  margins  into 
the  sound  tissue  on  both  sides.  Until  the  beginning  of  cicatri- 
zation the  wound  should  be  kept  open  by  probing  once  or  twice 
daily  with  a  blunt-pointed  stilet. 

Finally,  one  of  the  worst  forms  of  purulent  keratitis  occurs 
with  variola.  There  are  generally  deep  infiltrations,  connected 
with  great  irritability,  and  leading  to  slowly  progressive  destruc- 
tion of  the  cornea.  The  ulcer  shows  more  inclination  to  extend 
superficially  than  to  penetrate,  so  that  perforation  seldom  happens 
before  a  large  portion  of  the  cornea  is  destroyed.  Hypopion  and 
iritis  are  seldom  absent  in  this  form  of  purulent  keratitis.  The 
aifection  is  very  obstinate,  and  cannot  generally  be  successfully 
treated  by  atropine,  lukewarm  fomentations,  the  pressure-bandage, 
etc.  I  have  found  a  1  or  2  per  cent,  solution  of  the  nitrate  of 
quinia  useful  in  some  of  the  cases.  Iridectomy  was  generally 
necessary,  and  in  many  cases  was  of  decided  benefit. 

Those  cases  in  which  the  purulent  infiltration  and  ulceration 
begin  at  the  corneal  margin  are  to  be  classed  as  purulent  kera- 
titis. There  generally  also. develops  soon,  an  extensive  conjunc- 
tival swelling  with  muco-purulent  secretion.  Atropine  and  the 
pressure-bandage  if  necessary,  chlorine  water  or  a  1  to  2  per 
cent,  solution  of  nitrate  of  silver  where  there  is  great  conjunc- 
tival swelling,  are  the  suitable  remedies. 

Still  more  rarely  there  occur  near  the  margin  of  the  cornea,  but 
separated  from  it  by  a  zone  of  healthy  tissue,  small  purulent  in- 
filtrations, which  form  an  ulcer  parallel  to  the  corneal  margin. 
If  they  are  early  and  suitably  treated  with  the  remedies  above 
mentioned,  these  ulcers  heal  well.  If,  however,  they  have  once 
crept  around  more  than  half  the  circumference  of  the  cornea,  they 
threaten  great  danger  to  the  nutrition  of  its  centre.  It  becomes 
gray  and  clouded,  and  finally  necrotic. 

Neuro-paralytic  keratitis,  in  consequence  of  paralysis  of  the  fifth 
nerve,  is  a  rather  rare  disease.  The  sensibility  of  the  cornea, 
conjunctiva,  and  lids,  and  frequently  also  of  the  greater  part  of 
the  corresponding  half  of  the  face,  is  lost.      There  occur  upon 


NEURO-PARALYTIC    KERATITIS.  307 

the  cornea,  generally  at  its  centre,  a  gray  clouding,  and  soon  a 
loss  of  substance  by  ulceration.  Frequently  there  is  at  the  same 
time  a  noticeable  dryness  of  the  epithelial  covering  of  the  con- 
junctiva and  cornea. 

The  neuro-paralytic  inflammation  of  the  eyes  cannot  be  regarded 
as  a  direct  consequence  of  the  paralysis  of  sensation,  since  the 
experiments  of  jNleissner  and  Biittner*  have  proved  that  complete 
anaesthesia  may  exist  without  being  followed  by  keratitis.  The 
anatomical  examination  in  these  cases  showed  that  the  ophthalmic 
branch  at  the  Casserian  ganglion  was  not  cut  entirely  through, 
but  that  a  few  of  its  lower  fibres  were  not  divided.  On  the  other 
hand,  Snellen  has  shown  that  the  inflammation  of  the  eyes  can  be 
postponed  or  entirely  prevented  by  protecting  them  from  external 
irritation.  The  influence  of  the  division  of  the  nerve  may  be 
regarded  as  diminishing  the  eyes'  capacity  for  resistance,  so  that 
external  irritations,  which  under  normal  relations  were  harmless, 
now  cause  traumatic  inflammation. 

In  the  human  subject  the  course  of  these  cases  depends  upon 
the  nature  of  the  cause  of  the  paralysis  of  the  fifth  nerve.  Gen- 
erally there  are  extensive  central  lesions,  which  are  noticeable  in 
the  course  of  the  other  nerves,  the  facialis,  abducens,  etc. 

Von  Graefef  has  described  a  peculiar  form  of  corneal  ulceration 
as  the  result  of  interstitial  encephalitis.;];  The  condition  is  gen- 
erally bilateral,  but  the  second  eye  is  attacked  some  weeks  after 
the  first.  There  is  photophobia  in  the  diseased  eye ;  it  begins  to 
weep;  conjunctival  veins  and  episcleral  vessels  develop  upon  it, 
without  however  there  being  decided  injection.  A  small  part  of 
the  cornea,  generally  central  or  slightly  eccentric,  becomes  a  cloudy 
gray  yellow,  while  the  epithelium  covering  it  becomes  dull  and 
loses  its  mirror-like  surface.  The  infiltration  increases  in  thick- 
ness and  circumference,  and  leads  to  ulcerative  destruction  of  the 
cornea.     Finally  there  follow  purulent  iritis  and  panophthalmia. 

At  the  very  beginning  there  is  a  very  peculiar  behavior  of  the 
conjunctiva  oculi.  Below  and  at  the  sides  of  the  cornea  it  becomes 
dull,  dry,  and  dotted,  and  when  relaxed  by  rolling  of  the  eye,  it 


*  Henle  und  Pfeufer's  Zeitschrift,  3  R.,  B.  xvi. 
t  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  250. 

X  Tirchow,  Ueber  interstitielle  Encephalitis,  Arch.  f.  path.  Anat.,  B.  44, 
pag.  472. 


308  CORNEAL   ULCERS. 

gathers  up  into  small  perpendicular  folds.  It  loses  its  natural 
moisture  and  elasticity,  and  its  epithelium  is  not  reproduced. 
The  condition  may  be  called  acute  xerosis. 

The  cases  were  those  of  children  from  two  to  six  months  old, 
and  ended  fatally  in  consequence  of  encephalitis. 

Corneal  ulcerations,  which  could  not  be  arrested,  have  been 
observed  in  the  course  of  severe  constitutional  diseases,  such  as 
typhoid  fever,  complicated  scarlatina,  etc. 

CORNEAL   ULCERS. 

Corneal  ulcers  may  occur  in  various  ways.  The  most  frequent 
causes  are  injuries  of  all  kinds,  corneal  diseases  in  consequence  of 
conjunctival  affections,  for  instance,  severe  catarrhal  conjunctivitis, 
acute  and  chronic  blennorrhceal  processes,  diphtheritis,  trachoma, 
etc.,  and  finally  phlyctenular  and  purulent  keratitis  in  their  various 
forms.  The  treatment  of  the  ulcer  depends  upon  the  process 
which  caused  it,  and  therefore  need  not  here  be  repeated.  If  the 
ulceration  stop  before  a  large  portion  of  the  cornea  be  destroyed 
or  perforation  have  occurred,  the  loss  of  substance  is  generally 
replaced  by  new-formed  tissue,  which,  under  favorable  circum- 
stances, may  be  so  clear  as  not  to  be  detected  by  ordinary  daylight. 
By  focal  illumination,  however,  one  can  always  see  that  the  layers 
of  new-formed  tissue  are  not  so  transparent  as  those  of  the  normal 
corneal  substance;  indeed,  a  very  considerable  diminution  of  vision 
may  be  caused  by  these  opacities  which  can  be  seen  only  by 
focal  illumination.  Frequently  the  scar  tissue  is  so  thick  that  it 
is  noticeable  by  its  bright  color. 

The  new-formed  tissue  does  not  always  correspond  to  the  size 
of  the  defect ;  it  may  be  too  small,  as  in  the  case  of  corneal  facets, 
or  it  may  be  too  large,  forming  a  prominence ;  even  its  superficial 
extent  may  be  greater  than  that  of  the  original  loss  of  substance. 
The  mass  of  tissue  which  grows  up  from  the  bottom  of  the  ulcer 
often  finds  the  anterior  elastic  lamella  upon  the  margin  of  the 
ulcer  still  deprived  of  its  protecting  epithelium,  and  may  spread 
out  upon  it  beyond  the  limits  of  the  original  ulcer,  till  it  reaches 
the  epithelium.  If  now  the  epithelial  layer  be  renewed,  the  new- 
formed  tissue  will  be  covered  by  it.  In  this  manner  occur  many 
of  those  cases  in  which,  upon  anatomical  examination,  a  layer  of 
new-formed  tissue  is  found  between  the  epithelium  and  the  ante- 


CORNEAL    ULCEES.  309 

rior  elastic  membrane.  Large,  thick  corneal  scars  are  frequently 
penetrated  by  permanent  blood-vessels. 

If  perforation  occur  in  a  corneal  ulcer,  the  further  course  depends 
principally  upon  the  size  and  position  of  the  opening.  In  the 
first  place,  the  aqueous  humor  flows  out,  allowing  the  iris  and 
lens  to  come  in  apposition  with  the  posterior  surface  of  the  cornea. 
In  small  perforating  ulcers  the  opening  may  close  again  in  a  few 
days,  the  anterior  chamber  refill,  and  the  ulcer  heal,  leaving  a 
scar  more  or  less  visible. 

An  adhesion  of  the  iris  with  the  inner  opening  of  the  ulcer 
often  occurs  (anterior  synechia).  When  the  anterior  chamber 
refills,  that  part  of  the  iris  which  is  attached  to  the  cornea  is  lifted 
forward,  or,  if  the  adhesion  be  very  small,  only  a  part  of  the  stroma 
of  the  iris  is  drawn  forward  like  a  thread,  while  the  rest  of  the 
iris  remains  in  its  normal  position.  In  fresh  cases  it  is  sometimes 
possible  by  maintaining  atropine  mydriasis  to  cause  the  complete 
detachment  of  the  anterior  synechia. 

In  somewhat  larger  j^erforations  the  iris  generally  falls  forward 
and  adheres  to  the  margins  of  the  opening.  The  prolapsed  part 
of  the  iris,  which  is  exposed  to  all  kinds  of  external  irritations, 
may  now  swell  or  even  become  purulently  inflamed  and  be  the 
starting-point  of  a  purulent  irido-ehoroiditis. 

The  prolapsed  iris  is  generally  driven  forward  like  a  cyst,  by 
the  accumulation  of  the  aqueous  humor,  and  thus  new  parts  of 
the  iris  may  be  drawn  into  the  prolapse.  In  the  further  course 
of  the  cicatrization  the  distended  prolapsed  iris  may  become  flat- 
tened again;  but  frequently  the  cicatricial  tissue  does  not  prove 
strong  enough  for  this,  and  a  staphylomatous  cicatrix  is  formed 
(staphyloma  partiale). 

The  course  is  similar  when  the  entire  cornea  is  destroyed.  The 
iris,  which  is  laid  bare,  is  covered  with  a  new-formed  layer  of 
tissue,  and  becomes  distended  forward.  Later,  the  cicatrix  may 
flatten  or  may  remain  staphylomatous  (staphyloma  totale). 

The  treatment  indicated  by  these  processes  must  be  such  as  to 
avert  as  much  as  possible  the  dangers  connected  with  a  rupture  of 
the  ulcer.  If  the  floor  of  a  large  ulcer  be  bulged  forward,  per- 
foration may  certainly  be  expected,  and  accordingly  care  is  to  be 
taken,  first,  that  the  perforation  shall  be  as  small  as  possible,  in 
order  to  avoid  anterior  synechia  and  prolapsus  iridis,  and,  second, 


310  CORNEAL    ULCERS. 

that  the  escape  of  the  aqueous  humor  be  as  gradual  as  possible. 
If  there  be  a  sudden  and  extensive  rupture  of  the  floor  of  the 
ulcer,  the  aqueous  humor  will  be  forcibly  discharged,  the  iris 
driven  forward,  and  even  luxation  of  the  lens,  with  rupture  of  its 
capsule,  may  follow. 

Both  indications  may  be  fulfilled  by  the  artificial  perforation  of 
the  floor  of  the  ulcer,  allowing  the  gradual  escape  of  the  aqueous 
humor.  The  after-treatment  consists  in  keeping  the  patient  quiet 
in  bed,  and  using  atropine  and  the  pressure-bandage.  The  same 
treatment  is  indicated  after  spontaneous  perforation.  Distended 
prolapses  of  the  iris  may  at  first  be  left  to  themselves;  if,  how- 
ever, in  the  course  of  a  week  or  two  they  do  not  flatten  down  by 
cicatricial  contraction,  their  removal  is  necessary  in  order  to  guard 
against  the  development  of  a  partial  staphyloma.  Very  prom- 
inent, distended  prolapses  are  most  easily  removed  by  the  scissors. 
If,  however,  the  prolapse  rise  very  gradually  above  the  general 
surface  of  the  cornea,  its  base  is  to  be  transfixed  with  a  small  knife, 
and  one-half  or  more  of  the  prola[)se  is  to  be  separated  by  to-and- 
fro  cuts  as  the  knife  is  withdrawn.  The  flap  thus  formed  is  to  be 
seized  Avith  the  toothed  forceps,  and  the  excision  of  the  other  half 
completed  by  one  or  two  cuts  witii  the  scissors. 

The  practice,  here  and  there  recommended,  of  touching  the 
prolapse  of  the  iris  with  nitrate  of  silver  or  other  substances,  is  a 
very  uncertain  one,  and  in  no  way  to  be  preferred  to  its  excision. 

A  certain  rare  form  of  corneal  ulceration,  Avhich  occurs  generally 
in  aged,  poorly  nourished  individuals,  deserves  a  special  mention. 
It  begins  insidiously,  and  goes  on,  at  first,  with  scarcely  any  re- 
action, but  if  unchecked,  ends  in  the  destruction  of  the  cornea.  A 
loss  of  substance  is  first  noticed  at  the  margin  of  the  cornea.  It 
increases  slowly,  and  either  extends  along  the  margin  of  the  cornea 
in  the  form  of  a  furrow,  finally,  however,  destroying  the  centre, 
or  gradually  extends  over  the  surface  of  the  cornea  from  the  very 
first. 

The  upper  layers  of  the  cornea  break  down  without  there  being 
any  purulent  infiltration  to  be  seen,  either  about  the  margin  or  at 
the  bottom  of  the  ulcer.  The  deeper  layers  generally  remain  in- 
tact and  transparent;  still,  perforation  may  occur.  Cicatrization 
gradually  extends  from  the  margin  till  the  entire  surface  of  the 
cornea  is  changed  into  a  smooth,  vascularized  scar. 


COENEAL   OPACITIES.  311 


CORNEAL    OPACITIES. 

Corneal  opacities  are  the  permanent  traces  left  by  an  ulceration 
or  infiltration  of  the  cornea. 

The  influence  which  they  exert  upon  vision  depends,  in  the 
first  place,  upon  their  position,  whether  within  or  without  the 
pupillar  region.  It  must  be  remembered  that  the  pupillar  region 
of  the  cornea — that  is,  tiiat  portion  of  its  surface  through  which 
rays  of  light  can  enter  the  pupil — is  somewhat  larger  than  the 
pupil  itself,  because  the  rays  of  light  ]>roceeding  from  a  fixed 
point  are  made  to  assume  a  convergent  direction  by  the  refraction 
of  the  cornea.  Corneal  opacities  which  lie  external  to  the  pupil- 
lar region  cause,  therefore,  no  disturbance,  while,  when  all  that 
part  of  the  pupillar  region  which  serves  for  central  vision  becomes 
opaque,  it  is  evident  that  objects  lying  upon  the  visual  axis  can 
cast  no  retinal  image.  Direct  vision  is  prevented.  If  under 
these  conditions  a  part  of  the  periphery  of  the  cornea  remain 
transparent,  eccentric  vision  is  still  possible.  During  monoc- 
ular vision,  with  the  aifected  eye,  eccentric  fixation  takes  place, 
its  direction  being  determined  by  the  position  of  the  still  trans- 
parent portion  of  the  cornea;  if,  for  instance,  it  be  above,  then 
will  an  object  which  is  directly  in  front  be  seen  with  the  axis 
of  vision  directed  downward.  During  binocular  vision  that  par- 
ticular object  will  not  be  seen  with  the  affected  eye;  still  less  does 
this  condition  ever  cause  strabismus,  as  it  was  formerly  thought 
to  do. 

Corneal  opacities  which  are  smaller  than  the  pupillar  region 
and  absolutely  opaque,  and  not  complicated  with  anomalies  of 
curvature,  exercise  only  a  very  slight  influence  over  vision.  A 
simple  diminution  of  the  pupillar  region,  as,  for  instance,  by  look- 
ing through  a  small  opening,  does  not  diminish  the  acuteness  of 
vision.  But  if  these  corneal  opacities  be  not  absolutely  opaque, 
the  rays  penetrate  them  in  all  directions ;  a  flood  of  diffuse  light 
is  thrown  upon  the  retina,  and  the  distinctness  of  vision  is  thus 
interfered  with. 

Nevertheless,  it  appears  that  this  is  less  important  than  irregu- 
larities in  curvature  and  refraction,  which  distort  the  retinal 
images.  Corneal  opacities  have  been  already  mentioned  as  a 
frequent  cause  of  irregular  astigmatism  (page  64). 


312  CORNEAL   OPACITIES. 

.  If  we  suppose  the  cornea  to  be  composed  of  a  number  of  small 
parts,  having  each  a  different  curvature  and  refractive  power, 
their  focal  distances  will,  of  course,  vary.  Each  part  will  cast  its 
own  image,  which  will  interfere  with  those  cast  by  the  other  parts, 
and  this  irregularity  becomes  so  much  the  greater  when  not  only 
the  focal  distances  but  also  the  optical  axes  of  these  different 
parts  do  not  correspond  with  each  other.  Both  these  conditions 
exist  in  irregular  astigmatism,  caused  by  corneal  opacities,  as  may 
be  demonstrated  ophthalmoscopically. 

If  in  the  examination  in  the  upright  image  the  examiner  fixes 
some  sharply  defined  object  in  the  fundus,  a  retinal  vessel,  for 
instance,  and  if  he  then  makes  slight  movements  of  his  head,  so 
that  his  line  of  vision  successively  penetrates  various  neighboring 
portions  of  the  cornea,  which  vary  in  refraction  and  in  centring, 
a  remarkable  apparent  movement  of  the  ophthalmoscopic  image 
is  the  necessary  consequence.  This  is  still  more  evident  in  the 
examination  in  the  inverted  image,  if,  for  instance,  when  fixing 
upon  a  retinal  vessel  the  convex  lens  be  moved  slightly  to  and  fro' 
in  a  direction  perpendicular  to  the  course  of  the  vessel. 

In  irregular  astigmatism  the  ophthalmoscopic  image  of  the 
fundus,  as  well  as  the  retinal  image,  is  composed  of  several  images 
inaccurately  superimposed,  and  the  relative  position  ef  these  vari- 
ous images  varies  with  the  movements  of  the  convex  lens.  More- 
over,  when  the  optic  disc  is  fixed  and  these  movements  are  made, 
there  appears  to  be  a  remarkable  change  in  its  form. 

The  hurtful  influence  of  corneal  opacities  upon  vision  may  be 
shown  in  a  very  simple  manner  by  the  ophthalmoscopic  illumina- 
tion with  a  weak  reflecting  mirror, — that  is,  with  a  silvered  plane 
mirror,  or  Helmholtz's  reflecting  glass  plates.  Irregular  astigma- 
tism is  then  made  apparent  by  the  fact  that  during  slight  move- 
ments of  the  mirror  one  and  the  same  place  upon  the  cornea 
appears  alternately  dark  and  bright.  In  this  experiment  we 
examine  the  corneal  opacities  by  transmitted  light,  the  source  of 
the  light  which  causes  the  pupil  to  seem  illuminated  being  the 
image  of  the  flame  cast  in  the  fundus  of  the  eye  by  the  mirror, 
which  image  of  course  changes  its  place  with  every  movement  of 
the  mirror.  If  now  the  curvature  and  transparency  of  the  cornea 
be  normal,  slight  changes  in  the  position  of  the  source  of  light 
would  not  affect  the  amount  of  light  which  passes  through  the 


CORNEAL    OPACITIES.  313 

pupillar  region  of  the  eye  examined  to  that  of  the  examiner;  if, 
on  the  contrary,  irregularities  exist,  the  consequence  of  a  slight 
change  in  the  position  of  the  source  of  light  would  be,  that  in 
one  and  the  same  place  in  the  cornea  sometimes  more  and  some- 
times less  rays  of  light  would  be  so  refracted  as  to  correspond 
with  the  line  of  sight  of  the  observer ;  the  irregularly  curved 
places  will  therefore  appear  during  the  movements  of  the  mirror 
alternately  brighter  and  darker. 

The  disturbances  of  vision  caused  by  corneal  opacities  may 
generally  be  diminished  hy  Donders'*  stenopaic  apparatus,  which 
covers  the  entire  eye,  leaving  only  a  small  round  or  slit-shaped 
opening.  By  diminishing  the  light  falling  on  the  eye,  the  pupil 
dilates,  and  this  enables  the  patient  so  to  hold  the  diopter  that 
he  may  use  the  clearest  portion  of  his  pupillar  region. 

In  spite  of  the  very  considerable  improvement  in  vision  which 
may  be  caused  by  the  stenopaic  apparatus,  it  is  seldom  practicable 
to  allow  it  to  be  worn  as  spectacles,  for  it  makes  the  field  of  vision 
too  small,  and  its  position  can  be  altered  only  by  movements  of 
the  head  and  not  by  rolling  the  eyes.  It  may  be  best  employed 
for  reading. 

Treatment. — So  long  as  the  inflammatory  process  which  causes 
the  opacity  still  lasts,  the  proper  treatment  of  the  inflammation  is 
the  best  means  by  which  to  prevent  the  occurrence  of  opacities. 
But  if  the  opacities  remain  as  the  effect  of  a  process  which  has 
already  run  its  course,  their  disappearance  cannot  be  hoped  for. 
In  many  cases  in  which  the  entire  pupillar  region  is  occupied  by 
thick  opacities  while  the  periphery  of  the  cornea  is  still  clear, 
the  formation  of  an  artificial  pupil  is  indicated.  If  the  iris  has 
retained  its  normal  motility,  the  atropine  mydriasis  shows  us 
about  how  much  may  be  expected  from  an  artificial  pupil :  indeed, 
in  many  cases  the  question  arises  whether  continuous  and  suitably 
graduated  atropine  mydriasis  is  not  to  be  preferred  to  an  operation. 

If  an  operation  has  been  decided  on,  a  choice  is  to  be  made 
between  iridectomy  and  iridotomy.  Under  all  circumstances  the 
artificial  pupil  must  be  made  as  small  as  possible,  and  its  position 
carefully  chosen,  opposite  that  part  of  the  cornea  which  is  clearest. 
It  often  happens  that  against  the  black  background  of  the  new- 

*  Arch.  f.  Ophth.,  B,  i.  1,  pag.  291. 
21 


314  CORNEAL   OPACITIES. 

formed  pupil,  opacities  become  visible  which  could  not  before  be 
seen  over  the  lighter-colored  iris.  The  objection  to  be  made  to 
iridectomy  in  corneal  opacities  is,  that  the  artificial  pupil  generally 
proves  larger  than  is  desirable  for  optical  purposes ;  moreover,  in 
doing  the  operation  the  wound  must  be  made  at  the  margin  of 
the  cornea  close  to  the  new  pupillary  region,  and  there  is  danger 
of  its  causing  cicatrices,  opacities,  and  anomalies  of  curvature 
which  cause  optical  disturbances. 

The  operation  of  iridotomy  consists  in  making  a  straight 
incision  in  the  iris  from  its  pupillar  margin  toward  its  periph- 
ery. For  this  purpose  a  puncture  is  made  with  the  lance  knife 
in  the  margin  of  the  cornea  on  the  side  opposite  to  that  on  which 
the  iris  is  to  be  incised,  and  thus  it  hap])ens  that  the  wound  is 
almost  always  in  a  part  of  the  cornea  already  clouded.  It  is  well, 
after  the  lance  knife  has  been  slowly  inserted  until  a  wound  is 
made  3  or  4  mm.  in  length,  to  withdraw  it  quickly,  in  order  to 
retain  some  of  the  aqueous  humor  in  the  anterior  chamber. 
Wecker's*  forceps-like  scissors,  made  for  this  purpose,  are  then 
passed  into  the  anterior  chamber  with  one  blade  before  and  the 
other  behind  the  iris,  which  is  then  cut  through  by  quickly  closing 
the  scissors.  Great  care  must  be  taken  when  inserting  the  blade 
to  avoid  wounding  the  capsule  or  causing  luxation  of  the  lens.  The 
contraction  of  the  sphincter  of  the  iris  causes  the  wound  to  gape, 
so  as  to  open  an  artificial  pupil  of  sufficient  size. 

The  removal  of  a  corneal  opacity  by  an  operation  is  very  rarely 
possible.  In  a  case  described  by  Bowman,f  a  deposit  of  phos- 
phate and  carbonate  of  lime  had,  in  the  course  of  several  years, 
and  apparently  without  symptoms  of  inflammation,  accumulated 
beneath  the  unchanged  epithelium,  and  it  was  scaled  off  the 
cornea,  to  the  great  improvement  of  vision. 

A  very  peculiar  form  of  corneal  opacity  remains  to  be  men- 
tioned. It  is  a  band-like  stripe,  3  or  4  mm.  in  breadth,  which 
crosses  the  cornea  in  the  direction  of  the  palpebral  fissure.  The 
opacity  always  begins  at  the  extremities  of  the  horizontal  diam- 
eter of  the  cornea,  and  extends  gradually  toward  the  centre.    Its 

*Annales    iVOculistique,   tome    Ixx.  pag.  123,   and    Klin.  Monatsbl.    fiir 
Augenheilk.,  1873,  pag.  377. 
f  Lectures,  pag.  119. 


CORNEAL   STAPHYLOMA.  315 

color  is  so  slight  that  it  can  be  more  easily  seen  by  focal  illumi- 
nation than  by  daylight,  and  it  appears  to  be  composed  of  fine 
and  coarse  dots  and  flakes  immediately  under  the  epithelium.  It 
always  appears  upon  both  cornese,  although  not  always  in  the  same 
degree. 

The  condition  is  a  rare  one.  It  often  occurs  without  any  compli- 
cations, and  is  accompanied  only  by  those  disturbances  of  vision 
which  are  due  to  the  optical  relations,  as  may  be  demonstrated  by 
the  stenopaic  apparatus  or  by  atropine  mydriasis.  These  corneal 
opacities  are  oftener  seen  in  the  later  stages  of  irido-choroiditis, 
and  are  then  generally  noticeable  by  their  bright  color.  They 
also  occur  in  connection  with  glaucoma.* 

CORNEAL   STAPHYLOMA. 

The  name  staphyloma  designates  a  distention  of  the  corneal 
cicatrix  to  whose  inner  surface  the  iris  has  become  adherent.  The 
staphyloma  is  called  total  when  it  involves  the  whole,  and  partial 
when  it  involves  only  a  part  of  the  cornea. 

When  the  entire  cornea,  or  the  greater  part  of  it,  is  destroyed 
by  ulceration  and  the  iris  exposed,  a  membranous  cicatrix  forms 
over  it,  and  this  is  driven  forward  by  the  accumulation  of  aqueous 
humor  behind  it.  Later,  the  cicatricial  tissue  may  flatten  down 
and  heal  fast,  or  it  may  soften  under  the  influence  of  new  inflam- 
matory irritation  and  again  bulge  forward.  This  process  may  be 
repeated  several  times. 

But  even  small  corneal  ulcers,  which  have  destroyed  only  the 
central  part  of  the  cornea,  may  lead  to  staphyloma  by  the  adhesion 
of  the  entire  pupillar  margin  of  the  iris  to  the  cicatrix.  A  restora- 
tion of  the  anterior  chamber  under  these  circumstances  is  impos- 
sible. The  iris  remains  in  apposition  with  the  posterior  surface  of 
the  cornea,  the  aqueous  humor  accumulates  behind  it,  and  causes 
a  stretching  and  protrusion  both  of  the  cornea  and  of  the  iris. 

In  both  cases  there  finally  develops  a  tumor,  which  protrudes 
from  the  palpebral  fissure,  and  which  the  lids  can  cover  only  by  a 
certain  tension.  Both  the  deformity  and  the  continual  irritation 
kept  up  by  the  staphyloma  indicate  its  removal  by  operation. 

The  staphyloma  is  transfixed  at  its  base  with  a  cataract  knife, 

*  Von  Graefe,  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  139. 


316  CORNEAL    STAPHYLOMA. 

and  one-half  of  it  detached ;  the  flap,  is  then  seized  with  the 
toothed  forceps,  and  the  removal  completed  with  the  scissors 
curved  on  the  flat. 

The  loss  of  substance  caused  by  this  operation  is  of  course  as 
large  as  the  base  of  the  excised  staphyloma,  and  it  may  be  left  to 
heal  spontaneously  under  a  pressure-bandage. 

In  order  to  hasten  healing,  Critchett*  has  proposed  to  close  the 
wound  with  sutures,  which  should  be  inserted  before  the  staphy- 
loma is  removed.  Critchett  passed  five  curved  needles  through 
under  the  base  of  the  staphyloma,  which  was  then  removed  and 
the  sutures  united.  Since  in  most  cases  of  staphyloma  the  base 
corresponds  nearly  to  the  corneo-scleral  boundary,  the  sutures 
must  be  passed  through  the  ciliary  body.  ■  The  great  danger  at- 
tending all  wounds  in  this  region  must  be  remembered,  and  this 
danger  is  increased  by  the  fact  that  the  threads  which  act  as  a 
foreign  body  must  be  allowed  to  remain  a  long  time.  Knappf 
has  proposed,  therefore,  to  include  only  the  conjunctiva  in  the 
sutures.  The  simplest  method  is  to  insert  about  four  threads  in 
the  conjunctiva  above  and  below  the  staphyloma.  The  })ortions  of 
the  threads  extending  across  the  staj^hyloma  in  a  vertical  direction 
are  then  pushed  aside,  the  staphyloma  is  removed,  the  sutures 
tied,  and  a  pressure-bandage  applied.  In  most  cases,  however, 
the  sutures  cut  through  the  conjunctiva  after  two  or  three  days, 
and  the  wound  then  remains  open,  till  after  four  to  six  weeks  it 
^closes  by  cicatrization.  The  matter  is  not  improved  by  previously 
detaching  the  conjunctiva  from  the  sclera  about  the  cornea  and 
inserting  the  threads  so  that  the  edges  of  the  conjunctiva  come  in 
apposition.  Even  then  the  conjunctival  wound  does  not  heal 
before  the  sutures  cut  through. 

Tiie  object  of  placing  the  sutures  before  removing  the  staphy- 
loma is  to  make  it  possjble  to  close  the  wound  immediately  and 
without  any  escape  of  the  vitreous.  But  if  the  operation  be  done 
during  deep  narcosis,  the  wound  may  be  closed  by  stitches  after 
the  removal  of  the  staphyloma  without  any  escape  of  the  vitre- 
ous. In  some  cases  I  have  therefore  operated  by  excising  from 
the  staphyloma  a  sufficiently  large  elliptical  piece  whose  longest 

*  Ophth.  Hosp.  Eep.,  iv.  1. 

t  Arch.  f.  Ophth.,  B.  xiv.  1,  pag.  273. 


CORNEAL,  STAPHYLOMA.  317 

diameter  corresponded  with  the  direction  of  the  palpebral  fissure. 
The  wound  is  made  with  an  acute  angle  at  either  end,  giving  it 
thus  a  form  suitable  for  direct  union.  The  upper  and  lower 
raai'gins  of  the  corneal  wound  are  then  brought  in  apposition  by 
catgut  sutures.  I  generally  neglect  the  enucleation  of  the  lens  in 
the  removal  of  total  staphyloma.  The  catgut  sutures  are  cut 
off  closely,  since  their  removal  is  unnecessary. 

Before  every  operation  for  staphyloma,  it  is  advisable  to  ascer- 
tain whether  there  is  good  perception  of  light.  If  there  be  not, 
there  exists  some  serious  intraocular  disease,  generally  excavation 
of  the  optic  disc.  Under  such  circumstances  the  removal  of  the 
staphyloma  by  suddenly  relieving  the  intraocular  pressure  may 
easily  cause  choroidal  hemorrhage,  which  may  be  so  severe  as  to 
force  out  the  entire  contents  of  the  eye.  At  all  events,  panoph- 
thalmitis follows,  with  a  tedious,  painful  healing  process,  and 
eventual  shrinkage  of  the  stump.  In  such  cases  the  question 
may  arise  whether  it  is  not  preferable  to  enucleate  the  eye  in  the 
first  place.  Even  when  there  is  good  perception  of  light,  and 
when  the  existence  of  intraocular  complication  is  therefore  not 
.probable,  the  operation  for  staphyloma  may  lead  to  purulent  cho- 
roiditis and  atrophy. 

Anatomical  examination  shows  a  staphyloma  to  consist  of  cica- 
tricial tissue,  which  on  its  anterior  surface  is  covered  by  epithelium 
arranged  in  several  layers,  while  its  intraocular  surface  is  covered 
by  the  remains  of  the  iris,  generally,  however,  only  by  the  uveal 
layer.  The  stroma  of  the  iris  disappears  in  the  adhesions  formed 
with  the  new  scar  tissue,  leaving  only  a  slight  trace  of  pigment. 
There  is  no  trace  of  either  an  anterior  or  a  posterior  elastic  lamina 
upon  jtlie  staphyloma.  The  anterior  elastic  membrane  is  seen 
broken  abruptly  oiF  at  the  margin  of  that  portion  of  the  corneal 
tissue  which  still  remains,  while  the  posterior  elastic  membrane 
is  folded,  rolled  together,  and  included  in  the  cicatricial  tissue. 
Flat,  non-staphylomatous  scars  in  the  cornea  present  exactly  the 
same  appearances. 

Staphylomatous  scars  vary  in  thickness.     They  are  generally 

thin,  but  sometimes  have  a  tliickness  of  2  or  3  mm. 

.  The  way   in   which   partial   staphyloma  occurs  is  as  follows. 

After  a  perforation  of  the  cornea  the  iris  falls  forward,  is  bulged 

outward  by  the  accumulation  of  the  aqueous  humor,  and  fails  to. 


318  CORNEAL   FISTULA. 

be  drawn  backward  to  its  normal  level  by  the  subsequent  cica- 
tricial contraction. 

Where  there  has  been  extensive  loss  of  corneal  substance  the 
occurrence  of  total  corneal  staphyloma  cannot  always  be  avoided, 
but  where  there  is  a  small  ulcer,  with  the  destruction  of  not  more 
than  one-third  of  the  cornea,  a  staphylomatous  cicatrization  should 
be  prevented  by  a  prompt  excision  of  the  prolapse.  If  this  be 
not  done,  and  a  permanent  staphylomatous  scar  be  allowed  to 
develop,  the  normal  curvature  of  the  portion  of  the  cornea  still 
remaininij;  transparent  is  soon  destroyed,  to  the  detriment  of  vision. 

A  partial  staphyloma  is  removed  in  the  same  way  as  a  larger 
prolapse  of  the  iris  or  a  total  staphyloma.  If  the  partial  staphy- 
loma develop  again  after  its  removal,  it  is  often  due  to  the  fact 
that  the  lens  is  luxated  and  presses  with  its  edge  against  the  scar. 
If  this  condition  can  be  recognized  during  the  operation  for  re- 
moving the  staphyloma,  it  is  best  to  open  the  capsule  and  extract 
the  lens.  Partial  staphyloma  is  often  observed  to  decrease  after 
iridectomy. 

Corneal  fistula  is  a  small  opening  in  the  anterior  chamber, 
through  which  the  aqueous  humor  continually  flows.  This  ex- 
ceptionally happens  after  wounds  or  operations  at  the  corneo-scleral 
boundary,  over  which  the  conjunctiva  heals,  while  a  small  portion 
of  the  corneal  wound  remains  open.  The  aqueous  humor  then 
accumulates  beneath  the  conjunctiva. 

Fistula  of  the  anterior  chamber  more  frequently  follows  corneal 
ulcers. 

Even  when  the  perforation  caused  by  a  corneal  ulcer  is  very 
small,  the  refilling  of  the  anterior  chamber  is  often  long  delayed; 
the  aqueous  humor  trickles  away  constantly,  and  the  iris  and  lens 
lie  against  the  posterior  surface  of  the  cornea.  Now  and  then  the 
fistula  closes  superficially,  some  aqueous  humor  accumulates,  but 
before  the  anterior  chamber  becomes  normally  filled  the  fistula 
opens  anew.  Even  after  complete  closure  of  the  fistula,  a  slight 
irritation  may  cause  it  to  reopen. 

This  condition  appears  to  develop  principally  when  the  iris  has 
become  adherent  to  the  perforation  of  the  ulcer. 

The  treatment  consists  in  a  continuance  of  the  means  indicated 
in  the  treatment  of  the  ulcer.  Often  the  fistula  does  not  close  till 
ithe  atropine,  which  up  to  that  time  had  been  in  use,  is  withheld. 


KEKATOCONUS.  319 

A  certain  degree  of  tension  upon  the  iris  attached  to  the  fistulous 
opening  appears  to  favor  the  iiealing.  The  curative  effect  of  Cala- 
bar beau,  which  Zehender*  observed  in  oue  case,  probably  depends 
upon  this.  In  one  case  of  corneal  fistula,  which  had  persisted  a 
long  time  and  had  resisted  all  other  means,  I  was  able  to  close  it 
permanently  by  introducing  a  fine  hook  in  the  fistulous  opening, 
raising  it  up  and  excising  its  walls  with  the  scissors. 

Corneal  fistulas  may  persist  a  long  tiuie  without  doing  any 
great  harm.  But  while  they  last,  the  degree  of  vision  and  the 
extent  of  the  visual  field  should  be  carefully  watched,  since,  in 
many  cases,  rapid  glaucomatous  blindness,  due  to  excavation 
of  the  optic  nerve,  comes  on  without  any  noticeable  external 
changes. 

Vesicles  sometimes  occur  upon  the  cornea  in  eyes  otherwise 
quite  normal,  and  without  any  previous  inflammatory  symptoms, 
but  they  are  more  frequent  in  eyes  which  have  a  long  time  been 
diseased.  They  have  been  most  frequently  observed  during  the 
course  of  interstitial  keratitis,  chronic  iritis,  and  glaucoma.  The 
vesicles  consist  simply  of  the  epithelium  raised  from  the  anterior 
elastic  lamina,  and  are  sometimes  quite  tense  and  sometimes  so 
relaxed  that  their  form  can  be  changed  by  pressure  on  the 
epithelial  covering. 

The  annoyances  which  they  cause  are  nearly  the  same  as  those 
of  a  foreign  body  irritating  the  cornea.  They  may  generally  be 
cured  by  simple  puncture.  Exceptionally,  however,  the  process  is 
obstinately  persistent.  Von  Hasnerf  was  able  to  cure  one  such 
case,  only  by  removing  the  anterior  lamellae  of  the  cornea,  corre- 
sponding to  the  part  upon  which  the  vesicles  persistently  recurred. 

KERATOCONUS. 

Keratoconus  is  a  change  in  the  form  of  the  cornea,  by  which 
it  loses  its  normal  curvature  and  becomes  more  or  less  pointed 
in  its  centre.  The  cornea  at  this  point  is  considerably  thinned, 
frequently  to  one-third  its  marginal  thickness.  In  one  case  ex- 
amined by  Hulke|  the  anterior  elastic  lamina  participated  in  this 
thinnin":,  while  the  membrane  of  Descemet  was  unchanged. 


*  Klin.  Monatsbl.,  vi.  pag.  35.  f  Klinische  Vortriige,  pag.  196. 

J  Ophth.  Hosp.  Rep.,  ii.  pag.  155.  , 


320  KERATOCONUS. 

The  thinning  and  pointing  of  the  centre  of  the  cornea  occur 
quite  gradually,  and  at  first  the  cornea  is  absolutely  clear.  Later, 
a  slight  gray  opacity  appears  at  the  apex  of  the  cone,  which  Hulke 
found  to  be  due  to  a  layer  of  elongated  nuclei  immediately  be- 
neath the  anterior  elastic  membrane,  and  a  transformation  of  the 
corneal  tissue  into  a  net-work  of  nucleated  fibres  surrounding 
clusters  of  large  spindle-shaped  cells. 

The  beginning  of  the  disease  is  generally  at  a  time  between  the 
fifteenth  and  the  twenty-fifth  year,  but  it  may  be  either  earlier 
or  later.  As  a  rule,  both  eyes  are  successively  affected,  and  gener- 
ally to  a  different  degree.  This  stretching  of  the  centre  of  the 
cornea  may  become  stationary  at  any  stage.  It  may  also,  though 
it  rarely  does,  begin  again  after  having  been  a  long  time  station- 
ary. Even  in  the  most  extreme  cases,  bursting  or  ulceration  of 
the  cornea  never  occurs.  There  is  no  increase  of  hardness  of  the 
eyeball. 

The  optical  consequence  of  the  increased  prominence  and  shorter 
curvature  of  the  centre  of  the  cornea  is  myopia.  But  at  the  same 
time  the  irregularity  of  the  corneal  curvature  makes  the  retinal 
imasres  likewise  so  irreg-ular  that  the  distinctness  of  vision  is 
greatly  interfered  with.  The  annoyances  are,  in  general,  those 
of  myopia  complicated  with  amblyopia. 

Such  patients  are  often  able  to  read  ordinary  print,  since  they 
hold  it  close  to  the  eye  and  so  receive  large  retinal  images.  Only 
a  slight  improvement  of  vision  for  distance  can  be  obtained  by 
concave  glasses. 

The  diagnosis  is  very  easy  after  the  condition  has  passed  a  cer- 
tain sta^e.  The  characteristic  change  in  the  form  of  the  cornea 
can  then  scarcely  be  mistaken.  Slight  degrees,  on  account  of  the 
irregular  astigmatism  connected  with  them,  are  easily  recognized 
with  the  ophthalmoscope. 

It  is  plain  that  no  kind  of  medication  can  be  expected  to  restore 
the  normal  curvature  of  the  cornea.  Operative  relief,  too,  is  quite 
limited. 

Iridectomy,  originally  proposed  by  Von  Graefe,*  would  in 
most  cases  do  more  harm  than  good,  since  the  circles  of  diffusion 
upon  the  retina  increase  with  the  size  of  the  pupil. 

*  ^rch.  f.  Ophth.,  B.  iv.  2,  pag.  271. 


WOUNDS    OF   THE    CORNEA.  321 

Bowman,*  therefore,  proposed,  by  the  operation  of  iridodesis,t 
to  lengthen  the  pupil  or  to  change  it  into  a  narrow,  vertical  slit 
by  two  such  operations  at  diametrically  opposite  points  at  the 
margin  of  the  cornea.  Still,  this  operation  does  not  relieve  the 
optical  disturbances  caused  by  the  irregular  curvature  of  the 
cornea.     It  simply  diminishes  the  size  of  the  circles  of  diffusion. 

Finally,  Von  Graefe|  tried  the  plan  of  provoking  an  ulcer 
upon  the  middle  of  the  cornea,  with  the  hope  that  the  contraction 
of  the  resulting  cicatrix  would  cause  an  improvement  in  the 
curvature.  For  this  purpose  a  slight  sujierficial  loss  of  substance 
is  caused  at  the  apex  of  the  cone.  A  small  knife  is  inserted  to  the 
dei)th  of  the  middle  layers,  and  its  point  brought  out  at  a  distance 
of  from  1  to  2  mm.  The  flap  thus  formed  is  seized  with  the  fine- 
toothed  forceps,  and  cut  off  close  to  its  base  with  the  scissors. 
The  small  defect  thus  caused  is  cauterized  a  day  or  two  later  with 
mitigated  nitrate  of  silver,  and  this  is  repeated  every  two  or  three 
days  till  a  sufficiently  intense  infiltration  process  is  set  up.  The 
ulcer  heals  finally  with  a  scar,  by  the  contraction  of  whi<;h  the 
abnormal  curvature  of  the  cornea  is  diminished. 

An  improvement  of  vision  cannot  be  expected  till  the  traumatic 
keratitis  has  run  its  course;  and* this  requires  from  two  to  three 
months. 

In  rare  cases  the  cornea  at  birth  is  much  too  large,  although 
perfectly  transparent. 

WOUNDS    OF    THE   CORNEA. 

Foreign  bodies  which  lodge  upon  the  cornea,  without  becoming 
imbedded  in  it,  are  generally  soon  removed,  on  account  of  the 
irritation  which  they  set  up.     Sometimes,  however,  these  objects 


*  Oplith.  Hosp.  Rep.,  ii.  pag.  166. 

f  The  operation  of  iridodesis  was  proposed  by  Critchett  (Ophth.  Hosp.  Rep., 
i.  pag.  220),  with  the  object  of  lengthening  and  at  the  same  time  retaining 
the  motility  of  the  pupil.  The  sphincter  iridis  must  be  spared,  and  not  ex- 
cised, as  in  iridectomy.  With  this  object  a  small  opening  is  made  in  the 
extreme  margin  of  the  cornea,  the  iris  is  grasped  with  the  forceps  not  far 
from  its  ciliary  insertion,  is  drawn  outward,  and  included  in  a  loop  of  thread, 
in  oi'der  to  prevent  the  spontaneous  retraction  of  the  small  prolapsus.  This 
operation  would  fulfil  many  therapeutic  indications  if  it  did  not  involve  the 
danger  of  irido-cyclitis  and  sympathetic  disease  oi"  the  other  eye. 

X  Arch.  f.  Ophth.,  B.  xii.  pag.  215. 


322  WOUNDS   OF   THE   CORNEA. 

remain  a  longer  time  and  maintain  a  chronic  inflammation.  This 
seems  oftenest  to  happen  with  the  husks  of  small  seeds,  but 
insects'  wings,  small  pieces  of  vegetable  membranes,  etc.,  have 
also  been  observed  to  remain  a  long  time  upon  the  cornea. 

The  removal  of  all  such  objects  is  most  easily  accomplished 
with  a  Daviel  spoon. 

'  It  much  oftener  happens  that  small  splinters  of  iron  (frequently 
red-hot),  pieces  of  glass  or  stone,  grains  of  powder,  etc.,  strike 
U])on  the  cornea  and  imbed  themselves  in  its  substance. 

It  is  generally  very  easy  to  see  the  foreign  body.  It  is  difficult 
only  when  very  small  dark  bodies  are  lodged  near  the  centre  of 
the  cornea  against  the  dark  background  of  the  pupil.  But  even 
then  the  diagnosis  is  easy  with  the  help  of  focal  illumination. 

The  removal  of  foreign  bodies  which  have  penetrated  the  cornea 
is  best  done  with  a  flat  curved  cataract  needle,  while  the  lids  are 
kept  apart  with  the  thumb  and  first  finger  of  the  left  hand.  With 
very  restless  patients  it  may  be  necessary  to  introduce  a  lid  sjiecu- 
lum  and  hold  the  eyeball  with  the  toothed  forceps. 

If  there  be  great  irritation,  it  is  well  to  drop  a  solution  of  atro- 
pine in  the  eye  after  the  removal  of  the  foreign  body. 

When  foreign  bodies  penetrjfte  the  cornea  and  pass  into  the 
anterior  chamber  they  cause  iritis,  and  if  they  wound  the  lens, 
traumatic  cataract  also. 

The  best  method  then  is  to  open  the  anterior  chamber  with  a 
lance  or  small  cataract  knife  at  the  margin  of  the  cornea  as  near 
the  foreign  body  as  possible,  and  attempt  its  removal  with  a  hook 
or  forceps.  If  the  foreign  body  be  lodged  in  the  iris,  iridectomy 
is  generally  unavoidable. 

As  a  rule,  however,  foreign  bodies  which  have  j^enetrated  the 
cornea  do  not  lodge  in  the  iris  or  lens,  but  find  their  way  to  the 
fundus  of  the  eye. 

Superficial  injuries  of  the  cornea  with  blunt  instruments,  cause 
often  only  a  circumscribed  loss  of  epithelium,  which  is  best  recog- 
nized by  showing  the  reflection  of  the  window-frame  as  it  passes 
over  the  edge  of  the  defect. 

These  injuries  generally  cause  great  irritation.  Atropine,  cold- 
water  dressings,  or,  when  these  are  not  enough,  the  pressure- 
bandage,  are  the  proper  remedies. 

Small  superficial  losses  of  substance  of  the  cornea  generally 


RELAPSING    CICATRICIAL,    KERATITIS.  323 

assume  very  soon  a  bright-gray  color,  and  appear  upon  focal  illu- 
mination to  be  surrounded  by  a  superficial,  diffuse,  dull-gray 
clouding.  The  process  may  go  on  to  healing,  or  the  spot  may 
assume  a  more  yellowish- white  color,  and  there  generally  appear 
in  the  deeper  parts  of  the  cornea  peculiar,  striated,  gray  opaci- 
ties, 2  or  3  mm.  in  length,  which  are  very  apparent  on  focal 
illumination.*  If  properly  treated  from  the  very  first,  these 
injuries  almost  invariably  run  a  favorable  course.  Quiet,  anti- 
phlogistic diet,  cold-water  dressings,  and  atropine  are  generally 
sufficient.  Neglect  of  these  cases  is  very  apt  to  lead  to  purulent 
keratitis. 

Very  slight  wounds  of  the  cornea  often  leave  behind  them  a 
peculiar  form  of  relapsing  keratitis.  After  slight,  even  imper- 
ceptible causes,  there  occur  the  same  complex  symptoms  as  with 
traumatic  keratitis,  namely,  swelling  of  the  lids,  lachrymation, 
pains  in  the  eyes,  often  streaming  through  the  whole  distribution 
of  the  fifth  nerve,  photophobia,  contraction  of  the  pupil,  injection 
of  the  conjunctiva  sclerfe,  and  hyperemia  of  the  crowded,  radi- 
ating, fine  conjunctival  vessels  about  the  margin  of  the  cornea. 
Upon  the  cornea  is  a  small,  gray,  often  swollen  opacity,  with  or 
without  loss  of  its  epithelium.  It  is  often  remarkable  how  very 
slight  are  the  changes  visible  in  the  cornea  in  comparison  with 
the  intensity  of  the  inflammatory  symptoms.  The  treatment  at 
first  is  the  same  as  that  of  traumatic  keratitis.  If  the  irritable 
condition  has  lasted  a  long  time,  warm  fomentations  are  better 
than  cold.  As  after-treatment  it  is  well  to  continue  for  some  time 
dusting  calomel  into  the  eye. 

Similar  cases  of  cicatricial  keratitis  also  occur  in  non-traumatic 
scars. 

Perforating  wounds  of  the  cornea  vary  greatly  according  to 
their  nature.  Accidental  wounds  of  course  vary  in  size,  and  are 
generally  more  or  less  bruised.  In  most  cases  the  aqueous  humor 
flows  away  immediately,  and  if  the  wound  be  not  too  small  there 
is  prolapse  of  the  iVis.     Frequently  there  is  at  the  same  time  a 

wound  of  the  lens  and  traumatic  cataract. 

I 

*  These  deep-gray,  striated  opacities  occur  not  only  in  traumatic  keratitis, 
as,  for  instance,  in  all  wounds  caused  by  operations  upon  the  cornea,  but  also 
very  often  in  keratitis  of  any  form,  and  cannot  therefore  be  regarded  as  an 
independent  form  of  disease.     They  generally  disappear  entirely. 


324  TUMORS  OF  THE  CORNEA. 

Absolute  rest,  atropine,  and  the  pressure-bandage  are  generally 
the  first  indications  to  be  fulfilled  in  perforating  corneal  wounds. 
If  prolapse  of  the  iris  has  occurred,  it  is  but  seldom,  and  then 
only  during  the  first  few  hours  after  the  injury,  that  its  reposition 
is  possible.  The  reposition  is  best  attempted  during  chloroform 
narcosis,  by  rubbing  lightly  with  the  upper  lid,  or  having  at- 
tempted this,  the  aqueous  hnmor  contained  in  the  prolapse  may 
be  emptied  into  the  anterior  chamber  by  suitable  direct  pressure, 
made  with  a  Daviel  spoon,  and  then  the  attempt  at  reposition 
begun  anew ;  if  it  be  not  successful,  the  prolapse  should  be  cut 
away  with  the  scissors. 

The  inflammation  excited  by  wounds  in  the  cornea  may  cause 
its  destruction  to  a  greater  or  less  extent,  or  may  set  up  inflam- 
mation in  the  deeper  parts  (irido-choroiditis  traumatica)  ending 
in  suppuration  and  atrophy  of  the  eye,  or  in  blindness  with  the 
development  of  scleral  staphyloma. 

Those  wounds  which  occur  at  the  junction  of  the  sclera  with 
tlie  cornea,  involving  at  the  same  time  the  ciliary  body,  are  most 
dangerous,  for  the  reason  that  they  much  oftener  than  any  others 
cause  sympathetic  disease  of  the  other  eye. 

Injuries  to  the  cornea  from  substances  Avhich  act  chemically,  as, 
for  instance,  burns  from  melted  metals,  mineral  acids,  lime,  etc., 
are  generally  of  a  very  dangerous  character.  They  are  often  very 
extensive,  not  only  involving  the  greater  part  of  tlie  cornea  but 
also  extending  into  the  conjunctiva,  and  therefore  generally  cause 
syrablepharon.  There  often  develops  about  the  wound  in  the 
cornea  a  purulent  inflammation,  which  may  extend  over  the  whole 
cornea,  or  even  into  the  iris  and  choroid,  thereby  causing  panoph- 
thalmitis. Even  where  the  course  is  more  favorable,  there  often 
remains,  as  a  consequence  of  the  intense  traumatic  keratitis,  a 
clouding  of  parts  of  the  cornea  not  directly  injured. 

Tumors  of  the  cornea  are  generally  situated  upon  its  margin, 
and  often  extend  over  upon  the  conjunctiva  or  down  into  the 
sclera. 

The  first  to  be  mentioned  are  the  congenital  dermoid  tumors, 
which  vary  from  the  size  of  a  hemp-seed  to  that  of  a  pea,  and 
are  frequently  covered  with  hair.  If  they  become  annoying  they 
should  be  seized  with  the  toothed  forceps  and  removed  with  the 
cataract  knife. 


TUMORS    OF    THE    CORNEA.  325 

Cancroid  in  this  region  may  begin  upon  either  the  cornea  or 
the  conjunctiva. 

Melanoma  and  melano-sarcoma*  of  the  eye  develop  usually 
upon  the  margin  of  the  cornea,  and  it  is  generally  only  at  this 
place  that  they  are  firmly  attached  to  the  wall  of  the  eye;  poste- 
riorly they  are  continuous  with  the  conjunctiva,  and  movable  with 
it  upon  the  sclera ;  anteriorly  they  grow  over  the  cornea,  and  may 
thus  entirely  destroy  vision,  while  the  eyeball  presents  only  the 
appearance  of  a  tumor  projecting  from  the  palpebral  fissure. 
Nevertheless,  the  extirpation  of  the  eye  should  not  be  immediately 
resorted  to,  since  the  removal  of  these  tumors  from  the  sclera  is 
not  difficult,  and  they  do  not  penetrate  into  the  substantia  propria 
of  the  cornea.  They  may,  therefore,  be  easily  peeled  off,  leaving 
only  an  unevenness  of  the  epithelium,  which  soon  becomes  smooth. 
At  the  corneo-scleral  boundary,  the  place  of  origin  of  these  mor- 
bid growths,  the  extirpation  must  be  made  with  great  care  and 
thoroughness. 

The  arcus  senilis,  or  gerontoxon,  is  scarcely  to  be  classed  among 
the  pathological  affections  of  the  eye,  since  it  invariably  occurs  in 
old  age.  The  brighter  color  seen  about  the^  margin  of  the  cornea 
is  due  to  a  fatty  degeneration,  both  of  the  intercellular  substance 
and  of  the  corneal  corpuscles. 

*  Virchow,  Geschwiilste,  B.  ii.  pag.  122  and  279. 


DISEASES  OF  THE  SCLERA. 


ScLERiTis  AND  EPISCLERITIS. — The  inflammation  of  the  epi- 
scleral and  scleral  tissue  is  characterized  by  circumscribed  hyper- 
semia  and  swelling  of  a  region  generally  some  millimetres  distant 
from  the  margin  of  the  cornea. 

The  hypersemia,  which  is  at  first  bright  red,  becomes  darker  in 
time,  assuming  a  violet  shade,  while  the  swelling  is  sometimes  flat, 
gradually  disappearing  in  the  general  surface  of  the  sclera,  some- 
times circumscribed,  forming  a  hemispherical  prominence  of  per- 
haps the  size  of  a  pea.  In  the  latter  case  the  aifeetlon  very  much 
resembles  the  broad  phlyctenular  conjunctivitis,  but  differs  from 
it  in  the  fact  that  the  infiltration  is  not  in,  but  under  the  con- 
junctiva. 

In  cases  where  the  course  is  favorable,  the  swelling,  in  the  course 
of  several  weeks  or  months,  gradually  disappears,  the  violet  shade 
passing  into  a  slate-gray  and  then  into  a  lead-colored  spot,  which 
may  finally  fully  disappear,  or  may  remain  as  a  slight  discolor- 
ation. 

We  may  distinguish  a  simple  scleritis  from  that  form  compli- 
cated with  keratitis  and  iritis.  In  simple  scleritis  the  annoyances 
are  generally  not  very  great;  still,  the  acute  stage  may  be  accom- 
panied by  quite  severe  pain.  The  course  of  the  disease  in  each 
centre  of  inflammation  requires  generally  from  four  to  six  weeks; 
still,  the  entire  process  may  be  very  much  prolonged,  from  the 
fact  that  several  attacks  of  episcleritis,  affecting  different  localities, 
follow  one  after  the  other. 

Frequently  there  seem  to  be  a  predisposition  to  the  disease  and 
a  tendency  to  relapses. 

At  first  a  derivative  treatment,  by  mild  cathartics,  etc.,  is  indi- 
cated. Where  there  is  severe  pain,  and  in  general  during  the 
progressive  stage  of  the  inflammation,  good  results  often  follow 
the  use  of  atropine.  If  this  do  not  prove  sufficient,  lukewarm 
fomentations,  or  dry  warmth,  or  morphine  injections  in  the  supra- 
326 


SCLERITIS    AND    EPISCLERITIS.  327 

orbital  region,  or,  if  necessary,  leeches  on  the  temple,  should  be 
tried.  In  the  later  stage,  calomel  dusted  into  the  eye,  hastens  the 
resorption  of  the  exudate. 

Simple  non-complicated  scleritis  may,  however,  become  annoy- 
ing, partly  by  pain,  partly  by  its  tedious  course  and  frequent 
relapses.  As  a  general  thing,  however,  a  good  prognosis  may  be 
made.  On  the  contrary,  the  form  which  is  complicated  with 
keratitis  and  iritis  is  a  very  dangerous  disease. 

In  these  latter  cases  the  scleritis  generally  begins  with  very 
severe  symptoms.  After  there  have  existed  for  some  days  the 
symptoms  of  a  severe  inflammation  of  the  eye,  with  excessive  in- 
jection of  the  conjunctiva  throughout  its  whole  extent,  lachryma- 
tion,  pain,  etc.,  but  still  without  special  localization,  there  appears 
a  distinct  swelling  of  the  sclera,  either  occupying  a  greater  or  less 
space  about  the  cornea,  or  forming  a  livid  gray-red  hemispherical 
elevation.  Several  such  swellings  may  appear  at  the  same  time. 
After  some  days  there  develops  in  the  neighboring  portion  of  the 
cornea  a  grayish-white,  opaque  infiltration,  which  may  extend  to 
or  even  beyond  the  centre  of  the  cornea,  while  its  neighboring 
parts  show  a  smoky  clouding.  These  centres  of  inflammation  in 
the  sclera  and  cornea  are  both  painful  and  tender  under  the 
slightest  touch. 

The  participation  of  the  iris  is  shown  by  adhesions  of  its  pu- 
pillar  margin  with  the  capsule  of  the  lens. 

This  complicated  form  of  scleritis  is  in  every  respect  a  more 
severe  disease  than  the  simple  one.  The  inflammatory  attacks  are 
more  painful  and  tedious,  the  relapses  are  more  frequent,  and  may 
finally  cause  blindness.  The  intensity  of  the  inflammatory  process 
in  the  sclera  frequently  causes  a  thinning  of  the  place  affected ;  it 
becomes  more  yielding,  and  a  staphyloma  sclerse  is  the  result. 
In  this  way  the  entire  anterior  portion  of  the  sclera  may  become 
distended  and  covered  with  a  number  of  dark  prominences  about 
the  size  of  a  pea.  Frequently  the  cornea,  too,  participates  in  this 
process  of  stretching  and  enlargement. 

In  other  cases,  in  which  the  thinning  of  the  anterior  portion  of 
the  sclera  is  more  uniform,  the  eye  assumes  the  form  of  a  pear,  so 
that  its  cornea  projects  farther  forward  than  that  of  the  other  eye. 

The  grayish-white  infiltrated  portions  of  the  cornea  do  not 
clear  up  again  ;  thick  bright  spots  remain,  so  that  when  the  re- 


328 


STAPHYLOMA    OF    THE    SCLERA. 


lapses  have  been  frequent,  scarcely  a  perfectly  clear  place  in  the 
cornea  remains.  Finally,  the  adhesion  of  the  entire  margin  of 
the  iris  to  tlie  capsule  of  the  lens  brings  with  it  all  the  clangers 
connected  with  chronic  iritis. 

The  treatment  during  the  progressive  stage  should  be  deriva- 
tive and  antiphlogistic,  including  local  blood-letting,  cold-water 
dressings,  cathartics,  etc.  Atropine  is  to  be  used  from  the  very 
first,  and  continued  as  long  as  the  inflammation  lasts.  In  the 
later  stages  of  the  disease,  after  the  irritability  has  passed  away, 
calomel  dusted  into  the  eye,  or  weak  mercurial  precipitate  salve 
(1  per  cent.),  does  good  service. 

If  the  whole,  or  nearly  the  whole,  margin  of  the  iris  have  become 
adherent  to  the  capsule  of  the  lens,  the  operation  of  iridectomy  is 
indicated  in  order  to  avert  the  dangers  threatened  by  this  condition. 


STAPHYLOMA    OF    THE   SCLERA. 

The  so-called  '^  staphyloma  posticum  Scarpse,"  and  the  circum- 
scribed scleral  ectasise  which  occur  in  the  posterior  part  of  the 
eye,  have  already  been  mentioned  on  pages  33  and  45.  We  have 
here  to  consider  the  staphylomas  which  occur  in  the  equatorial 
and  anterior  part  of  the  sclera. 

They  consist  of  more  or  less  sharply  defined,  dark-bluish  prom- 
inences projecting  above  the  general  surface  of  the  sclera,  either 
isolated  or  in  considerable  numbers  near  one  another.  The  last, 
for  instance,  may  be  the  case  near  the  cornea,  which  may  be  sur- 
rounded by  a  more  or  less  complete  circle  of  such  prominences,  or 
the  same  appearance  may  be  presented  at  the  equatorial  part  of 
the  eye. 

Among  the  diseases  which  may  lead  to  the  development  of  such 
staphylomas,  we  have  already  mentioned  that  form  of  scleritis 
which  is  connected  with  infiltration  of  the  cornea  and  with  iritis. 

Cicatricial  staphyloma  of  the  cornea  may  extend  to  the  adjoin- 
ing portion  of  the  sclera.  Under  these  circumstances  the  usual 
demarcation  at  the  base  of  the  staphyloma  is  absolutely  wanting  ; 
the  anterior  portion  of  the  eye  assumes  a  conical  shape,  and  the 
staphyloma  without  any  sharply  defined  limits  extends  back  to 
the  equatorial  part  of  the  sclera.  These  are  always  cases  of  deeply 
disorganized  eyes,  in  which  generally  there  is  excavation  of  the 
optic  nerve,  in  consequence  of  increased  intraocular  pressure. 


STAPHYLOMA    OF    THE    SCLERA.  329 

Choroiditis  is  the  most  frequent  cause  of  scleral  staphyloma, 
especially  tliose  forms  of  choroiditis  which  follow  upon  iritis  with 
absolute  closure  of  the  pupil,  upon  traumatic  irido-choroiditis,  and 
upon  the  later  stages  of  glaucoma. 

In  almost  all  these  cases  there  is  blindness  from  excavation  of 
the  optic  nerve  in  addition  to  the  scleral  staphyloma. 

Intraocular  tumors  may  likewise  cause  staphyloma ;  sometimes 
by  consecutive  choroiditis,  sometimes  by  the  sclera  being  directly 
forced  out  by  the  tumor. 

Finally,  cases  occur  both  congenitally  and  later  in  connection 
with  some  of  the  above  named  diseases,  in  which  the  size  of 
the  eye  increases  nearly  uniformly  in  all  its  diameters,  and  to 
which  is  given  the  name  hydrophthalmus  or  buphthalmus.  The 
cornea,  too,  generally  participates  in  the  general  distention,  and 
becomes  therefore  flatter.  In  this  condition  there  is  generally 
absolute  blindness,  though  exceptionally  there  is  some  remnant 
of  vision  in  connection  with  a  high  degree  of  myopia. 

In  the  region  of  the  staphyloma  the  sclera,  choroid,  and  retina 
are  generally  closely  adherent  to  one  another.  Some  cases,  it  is 
true,  have  been  observed  in  which  the  sclera  has  been  raised  from 
the  internal  membranes,  but,  as  a  rule,  the  distention  and  atrophy 
atfect  all  three  of  the  coats.  By  this  process  the  retina  is  trans- 
formed into  a  net-work  of  indifferent  connective  tissue,  and  at 
the  same  time  is  often  infiltrated  with  pigment. 

The  consecutive  atrophy  of  the  choroid  generally  begins  with 
changes  in  the  pigment-cells  of  its  stroma;  they  lose  their  color 
and  disappear  gradually.  Soon  the  choroidal  capillaries  begin  to 
atrophy,  while  simultaneously  the  pigment  epithelium  loses  its 
pigment  and  its  regular  disposition  is  disturbed.  Even  the  large 
vessels  become  obliterated,  and  at  last  nothing  remains  of  the 
choroid  but  the  delicate  fibres  forming  the  so-called  elastic  net- 
work of  the  choroidal  stroma,  the  lamina  vitrea,  and  an  incom- 
plete and  irregular  covering  of  epithelium.  Even  these  remains 
of  tissue  may  so  disappear  that  nothing  is  left  but  a  thin  struc- 
tureless transparent  membrane.  On  the  other  hand,  cases  occur 
in  which  simultaneously  with  the  distention  of  the  choroid  the 
formation  of  new  tissue  seems  to  take  place  in  it.  One  would 
expect,  and  as  a  rule  it  is  generally  found,  that  the  consequences 
of  the  distention  of  the  choroid  are  a  diminution  of  the  calibre 

22 


330  STAPHYLOMA    OF   THE   SCLERA. 

of  its  capillaries,  an  extension  of  its  intervascular  spaces,  and  a 
separation  from  each  other  and  a  flattening  of  its  individual  epi- 
thelial cells;  but  cases  occur  in  which  the  appearances  are  directly 
the  opposite.  The  vessels  of  the  choroid  are  of  normal  or  more 
than  normal  breadth,  the  intervascular  spaces  are  smaller,  the 
pigment  epithelium  small  and  regularly  disposed. 

Staphyloma  in  the  region  of  the  ciliary  body,  and  extending  to 
the  margin  of  the  cornea,  generally  leads  to  destruction  of  the 
zonula  and  luxation  of  the  lens. 

Frequently  there  is  a  detachment  of  the  iris  from  the  ciliary 
body,  so  that  the  staphylomatous  distention  takes  place  between 
the  two.  In  other  cases  the  normal  connection  between  the  iris 
and  the  ciliary  body  is  maintained,  and  the  ridges  of  the  ciliary 
processes  are  found  in  front  of  the  staphyloma. 

The  therapeutic  indications  are  very  limited.  Vision  is  gen- 
erally destroyed,  and  even  if  it  be  not  entirely  lost,  that  fact  offers 
no  promise  for  an  improvement. 

Operative  interference  may  be  indicated  from  fear  of  sympa- 
thetic disease  in  the  other  eye,  especially  when  the  staphyloma  is 
of  traumatic  origin  and  when  the  eye  continues  painful.  Under 
such  circumstances  enucleation  of  the  eye  is  the  only  operation 
from  which  any  good  result  can  be  expected. 

Frequently  it  is  desirable  in  the  case  of  an  absolutely  blind  eye 
to  eifect  a  cosmetic  improvement  by  making  it  possible  to  wear 
an  artificial  one.  This  indication  is  not  an  easy  one  to  fulfil.  In 
these  seriously  disorganized  eyes  an  operation  by  the  method  de- 
scribed for  corneal  staphyloma,  is  very  likely  to  lead  to  intraocular 
hemorrhages  and  panophthalmitis,  which,  after  running  a  painful, 
tedious  course,  generally  leave  a  very  small  stump. 

On  the  other  hand,  enucleation  under  these  circumstances  is  apt 
to  leave  a  condition  very  unfavorable  for  the  use  of  an  artificial  eye. 
If  the  staphyloma  of  the  eyeball  has  been  considerable,  the  orbital 
fat  is  much  reduced,  and  as  a  consequence  the  conjunctival  sac  drops 
farther  back  in  the  orbit  than  otherwise.  The  artificial  eye  has  then 
only  slight  movement,  and,  moreover,  feels  so-  uncomfortable  that 
many  such  patients  finally  prefer  to  dispense  with  it  entirely. 

For  these  reasons  Von  Graefe*  made  the  attempt  to  cause  a 

*  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  105. 


STAPHYLOMA    OF   THE   SCLERA.  331 

moderate  degree  of  atrophy  in  the  eye  by  an  artificially  induced 
choroiditis.  An  ordinary  double  silk  thread  is  passed  through 
the  vitreous  body  in  such  a  way  as  to  include  in  the  suture  a 
scleral  bridge  8  or  10  mm.  in  breadth.  The  ends  of  the  thread 
are  to  be  simply  tied  in  a  loose  knot  to  keep  them  in  position. 
The  thread  should  not  be  passed  through  too  thin  a  portion  of 
the  sclera,  as  the  inflammation  there  set  up  might  be  too  severe. 
So  soon  as  an  evident  swelling  of  the  scleral  conjunctiva  and  a 
limitation  in  the  movements  of  the  eyeball  announce  the  begin- 
ning of  a  purulent  choroiditis,  the  threads  should  be  removed  and 
warm  fomentations  or  cataplasms  applied. 

If  there  be  any  symptoms  which  suggest  the  danger  of  a 
sympathetic  affection  of  the  other  eye,  this  method  should  not  be 
resorted  to,  and  enucleation  is  the  only  course  left. 


DISEASES  OF  THE  IRIS. 


Iritis  is  one  of  the  most  important  diseases  of  the  eye,  both  on 
account  of  its  sad  termination  in  many  cases,  and  on  account  of 
the  certainty  with  which  in  the  great  majority  of  cases  it  yiekls 
to  prompt  treatment. 

The  typical  form  of  this"  disease,  and  also  the  most  frequent,  is 
that  which  may  be  called  "Idiopathic  Iritis." 

During  its  first  stage  the  inflammatory  symptoms  are  often  so 
slight  as  to  escape  the  observation  of  the  i)atient.  His  attention 
is  first  arrested  by  an  indistinctness  of  vision  and  an  inability  to 
use  the  eyes  continuously. 

Soon,  however,  there  appears  a  deep-seated  injection  surrounding 
the  cornea,  due  to  a  hyperemia  of  the  radiating  vessels  occupying 
this  zone.  This  hypersemia  gradually  extends  to  the  superficial 
conjunctival  vessels.  There  is  generally  no  pain  at  first,  but  it 
becomes  very  severe  when  the  inflammation  reaches  its  highest 
point;  in  idiopathic  iritis  the  pain  stands  in  quite  uniform  relation 
to  the  severity  of  the  inflammation. 

The  pains  are  not  generally  limited  to  the  eye,  but  extend  upon 
the  supraorbital  region  or  over  the  distribution  of  the  sensitive 
branches  of  the  fifth  nerve.  They  generally  increase  at  night, 
and  may  become  insutferable.  A  copious  flow  of  tears  generally 
accoui panics  the  attacks  of  pain. 

The  clouding  of  the  cornea,  too,  stands  in  close  relation  to  the 
degree  of  the  inflammation.  At  first  and  in  mild  cases  it  merely 
dulls  the  appearance  of  the  eye,  and  the  patient  experiences  only 
a  slight  dimness  of  vision.  Even  by  focal  illumination  it  can 
often  be  detected  only  by  comparison  with  the  other  eye.  When 
the  inflammation  is  more  severe,  the  smoky-gray  opacity  of  the 
cornea  may  be  seen  with  the  naked  eye.  The  epithelial  surface, 
seen  through  a  magnifying  glass  and  by  focal  illumination,  appears 
punctated  and  uneven,  while  in  the  deeper  layers,  short,  gray 
striations  are  often  visible. 
332 


IDIOPATHIC    IRITIS.  333 

A  change  of  color  is  noticeable  in  the  iris,  appearing  first  in  the 
Gireulus  minor,  which  assumes  a  darker  color,  then  in  the  eirculus 
major,  which  in  blue  eyes  becomes  green  and  in  darker  eyes 
assumes  a  reddish  tinge.  The  change  in  color  is  probably  due  to 
a  saturation  with  blood-coloring  matter;  at  least  that  is  indicated 
by  the  fact  that  the  same  changes  occur  without  any  trace  of  iritis 
simply  in  consequence  of  a  subconjunctival  hemorrhage.  This 
observation  is  most  frequently  made  after  operations  for  squint. 
The  same  greenish  discoloration  of  the  iris  may,  however,  be  due, 
especially  where  there  is  choroiditis  with  hemorrhage  in  the 
vitreous,  to  a  yellow  color  of  the  aqueous  humor,  for  under  these 
circumstances,  when  the  cornea  is  punctured  and  the  aqueous 
humor  allowed  to  flow  away,  the  greenish  discoloration  of  the  iris 
is  not  unfrequently  seen  to  disappear  and  the  normal  color  to 
return. 

The  most  important  symptom  of  iritis  is  the  adhesion  of  tlie 
pupillary  margin  of  the  iris  with  the  capsule  of  the  lens.  This  can 
be  easily  recognized  by  focal  illumination,  and  where  there  is  any 
doubt  it  can  be  made  perfectly  evident  by  atropine.  The  pupillary 
margin  can  retract  toward  its  periphery  only  in  those  portions 
where  it  is  freely  movable ;  the  portions  which  are  adherent  to 
the  capsule  are  held  fast,  and  the  pupillary  opening  assumes  in 
consequence  a  very  irregular  form. 

Recent  adhesions  can  generally  be  torn  through  by  atropine, 
leaving  behind  pigment  upon  the  capsule,  while  if  the  adhesions 
have  existed  some  time  this  seldom  occurs.  Although  posterior 
synechise  are  caused  only  by  iritis,  still,  in  any  given  case,  \vhen 
the  diagnosis  of  iritis  cannot  be  made  out  from  other  signs,  there 
may  be  doubt  whether  the  synechia  is  a  symptom  of  an  existing 
aiFection  or  whether  it  is  the  residuum  of  a  i)rocess  which  has  long 
since  run  its  course. 

The  limitations  in  the  movements  of  the  iris  which  are  connected 
with  iritis  appear  to  depend  principally  upon  the  presence  of  these 
synechise.  At  first  and  so  long  as  no  synechise  are  present  the 
iris  remains  movable,  and  at  a  later  stage  it  still  moves  as  much 
as  these  adhesions  will  allow. 

It  is  only  in  the  most  severe  forms  of  idiopathic  iritis  that 
hypopion  or  an  exudate  having  a  fibro-gelatinous  appearance  is 
seen  in  the  anterior  chamber. 


334  RELAPSING    IRITIS. 

The  causes  of  this  form  of  iritis  are  often  of  a  rheumatic  nature, 
and  for  such  cases  the  name  "  rheumatic  iritis"  is  very  suitable. 
Frequently,  however,  no  cause  can  be  determined  with  certainty. 

In  the  majority  of  cases,  if  there  be  proper  treatment  from  the 
beginning,  recovery  is  reached  in  the  course  of  from  4  to  6  weeks. 
In  mild  cases  the  course  may  be  shorter,  but,  on  the  other  hand, 
relapses  may  greatly  delay  the  entire  disappearance  of  the  inflam- 
mation. 

The  treatment  of  idiopathic  iritis  is  very  simple.  The  eyes 
must  not  be  used ;  they  must  be  protected  from  all  harmful  influ- 
ences, such  as  dazzling  light,  smoke,  etc. ;  there  must  be  mild 
antiphlogistic  treatment,  and  still  more  important  and  indispensa- 
ble is  the  use  of  a  1  per  cent,  solution  of  the  sulphate  of  atropia. 
A  drop  of  this  must  at  first  be  placed  in  the  conjunctival  sac,  say 
every  five  minutes,  till  the  greatest  possible  mydriasis  is  obtained  ; 
after  this  only  so  much  atropine  is  to  be  used  as  is  necessary  to 
keep  the  pupil  dilated. 

Under  this  treatment  adhesions  between  the  capsule  of  the  lens 
and  the  margin  of  the  pupil,  if  they  have  not  existed  longer  than 
a  week,  are  generally  broken  up ;  older  adhesions  are  somewhat 
stretched,  but  generally  not  torn  through. 

Frequently  there  is  an  evident  remission  of  the  inflammation 
so  soon  as  a  sufficient  action  of  the  atropine  is  once  obtained,  and 
the  disease  then  goes  on  uninterruptedly  to  recovery.  In  severe 
cases  exacerabations  of  pain  recur  in  spite  of  complete  mydriasis, 
especially  at  night,  and  often  with  a  simultaneous  exacerbation  of 
all  the  inflammatory  symptoms,  such  as  increased  vascular  hyper- 
semia,  copious  lachrymation,  dense  clouding  of  the  cornea,  and  a 
recontraction  of  the  previously  dilated  pupil. 

Warmth  should  be  employed  during  the  attacks  of  pain ;  the 
eye  and  the  entire  half  of  the  face  should  be  covered  with  wad- 
ding, or,  when  the  pain  is  very  severe,  subcutaneous  injections  of 
morphine  may  be  made  in  the  supraorbital  region.  The  appli- 
cation of  leeches  upon  the  temple  is  also  often  useful  in  allaying 
the  pain. 

There  is  a  form  of  iritis  nearly  allied  to  the  idiopathic.  Its 
single  attacks  are  exactly  like  it,  and  in  its  whole  course  it  differs 
from  it  only  by  its  frequent  relapses.     Such  patients  are,  for  an 


i 


/  RELAPSING    IRITIS.  335 

indeterminate  length  of  time,  at  intervals  of  a  month,  or  longer, 
attacked  more  or  less  severely  with  iritis.  It  is  not  strange  that 
such  persons  generally  have  a  number  of  iritic  adhesions ;  and 
still  this  fact  is  the  only  ground  upon  which  is  based  the  gen- 
erally accepted  assertion  that  these  adhesions  are  the  cause  of  the 
relapses. 

The  possibility  of  such  a  causal  connection  of  course  cannot 
be  denied,  but  the  number  of  persons  who,  in  spite  of  numerous 
posterior  synechia,  do  not  suffer  from  relapsing  iritis  is  too  great 
for  us  to  admit,  without  hesitation,  that  the  synechia  are  the  cause 
of  the  relapses,  and,  moreover,  cases  occur  in  which  the  relapses 
appear  to  be  entirely  independent  of  any  adhesions.  I  have  seen 
patients  with  numerous  synechise  in  both  eyes,  who  for  a  long 
time  were  affected  with  relapsing  iritis  only  in  one  eye,  and  then 
suddenly,  without  any  apparent  cause,  the  disease  left  the  hitherto 
affected  eye  and  appeared  with  the  same  obstinacy  in  the  other. 
Finally,  I  have  known  cases  which  from  the  beginning  were 
properly  treated  with  atropine,  in  which  no  synechise  remained, 
and  which  still  were  not  protected  from  frequent  relapses  which 
occurred  without  any  apparent  cause. 

Often  the  causes  for  relapses  of  iritis  cannot  be  certainly  de- 
termined. They  may  be  due  to  syphilis,  but,  as  a  rule,  relapses 
due  to  that  cause  follow,  with  very  short  intervals,  one  after  the 
other.  Colds  are  often  regarded  by  the  patients  as  the  cause. 
In  many  cases  anomalies  in  the  circulation  of  the  nasal  mucous 
membrane  appear  to  precede,  and  stand  in  connection  with,  the 
attacks  of  iritis. 

In  all  these  cases  each  relapse  should  be  treated  according  to 
the  above  rules,  unless  the  etiology  of  the  particular  case  should 
suggest  special  indications. 

So  long  as  there  remains  a  freely  movable  portion  of  the  pupil- 
lary margin  between  the  adhesions,  relapsing  iritis  does  not  involve 
the  danger  of  blindness;  but  the  condition  is  a  very  serious  one 
so  soon  as  the  adhesion  of  the  entire  pupillary  margin  with  the 
capsule  has  formed.  This  condition  is  liable  to  occur  with  any 
neglected  or  badly  treated  acute  iritis.  When  it  does  occur,  the 
inflammatory  symptoms  are  generally  very  severe,  and  in  addition 
to  those  mentioned  above,  there  is  a  gray,  fibrinous,  coagulated 
exudate  in  the  pupil.     Simultaneously  the  periphery  of  the  iris 


336  ANNULAR    ADHESIONS. 

is  driven  forward.  It  may  still  be  possible,  by  the  energetic  use 
of  a  1  or  2  per  cent,  solution  of  atropine,  to  rupture  the  adhesions, 
and  so  avert  the  dangers  connected  with  them. 

These  annular  adhesions  of  the  pupillary  margin  occur  most 
frequently  in  consequence  of  chronic  relapsing  iritis.  The  mar- 
gin of  the  pupil  appears  attached  to  the  capsule  of  the  lens  by  a 
gray  band  of  new-formed  tissue,  of  a  greater  or  less  breadth. 
The  pupil  is  considerably  contracted,  and  either  has  no  further 
deposit  within  it,  or  may  be  covered  with  a  new-formed  tissue, 
in  which,  upon  microscopic  examination,  nvimerous  pigment-cells 
and  often  blood-vessels  are  found. 

So  long  as  a  small  portion  of  the  pupillary  margin  remains  free 
and  a  communication  exists  between  the  anterior  and  posterior 
chambers,  the  iris  remains  in  its  normal  position ;  but  so  soon  as 
the  annular  adhesion  of  the  margin  of  the  pupil  becomes  complete, 
the  eye  is  in  great  danger.  The  periphery  of  the  iris  is  driven 
forward  by  the  accumulation  of  fluid  in  the  posterior  chamber, 
so  that  the  margin  of  the  pupil  appears  sunken  like  a  crater. 
The  different  portions  of  the  periphery  of  the  iris  are  geneially 
not  uniformly  driven  forward,  but  are  somewhat  irregularly  prom- 
inent,— partly  because  some  portions  of  the  tissue  of  the  iris  are 
more  distensible  than  others,  and  partly  because  the  adhesion  in 
every  place  is  not  confined  simply  to  the  margin  of  the  iris,  l)ut 
extends,  at  certain  points,  more  or  less  outward  toward  the  peri]>h- 
ery  of  the  uveal  layer. 

The  fluid  accumulated  in  the  posterior  chamber  consists  prob- 
ably of  aqueous  humor  mixed  Avith  exudates;  at  all  events,  it 
appears  of  a  yellow  color  when  it  flows  out  during  the  operation 
of  iridectomy.  The  attacks  of  iritis  now  follow  very  rapidly  one 
after  the  other,  or,  in  consequence  of  these  frequent  exacerbations, 
there  develops  a  chronic  inflammatory  condition,  which  generally 
extends  to  the  choroid.  In  this  manner  there  generally  comes  on 
a  clouding  of  all  the  refracting  media.  The  acute  inflammatory 
attacks  are  accompanied  by  clouding  of  the  cornea,  the  disease 
extends  to  the  choroid,  and  then  appears  a  diffuse  clouding  of  the 
vitreous  body,  and  at  a  later  stage,  opacity  of  the  lens. 

The  loss  of  vision  does  not,  however,  depend  simply  upon  the 
clouding  of  the  refracting  media.  Where  the  disease  lasts  a  long 
time,  severe    intraocular    complications   are    sure   to   occur.     In 


IRIDO-CHOROIDITIS.  337 

most  cases  these  eyes  become  abnormally  soft,  and  finally  atrophic, 
bnt,  on  the  other  hand,  increased  intraocular  pressure  and  excava- 
tion of  the  optic  disc  also  occur,  and  not  infrequently  end  in 
staphyloma  of  the  sclera. 

When  these  complications  begin  to  develop,  the  consequence  is 
that  vision  becomes  much  poorer  than  can  be  explained  from  the 
condition  of  the  pupil,  which  may  be  distinctly  seen  by  focal  illu- 
mination. The  field  of  vision  should  be  tested  with  great  care, 
since  any  defects  in  it  always  indicate  some  serious  intraocular 
complication,  generally  excavation  of  the  optic  nerve  or  detach- 
ment of  the  retina. 

Among  the  objective  symptoms,  the  resistance  of  the  eyeball  is 
to  be  j)articular]y  observed.  Increased  hardness  indicates  optic- 
nerve  excavation,  decreased  hardness  indicates  detachment  of  the 
retina,  or  a  slight  atrophy  of  the  vitreous  body,  due  to  an  in- 
flammatory degeneration  of  the  retina  dependent  on  a  chronic 
choroiditis. 

It  is  generally  difficult  or  impossible  to  make  an  exact  ophtlial- 
moscopic  diagnosis  of  the  complication,  on  account  of  the  contrac- 
tion of  the  pupil  and  the  opacities  in  the  refracting  media. 

It  is  noticeable  that  this  form  of  iritis  in  the  majority  of  cases 
exists'  in  both  eyes  at  the  same  time,  although  in  different  stages 
of  development.  It  is  therefore  not  improbable  that  it  is  due  to 
some  unknown  anomaly  in  the  constitution  or  perhaps  in  the  eyes 
of  the  patient. 

When  adhesions  have  formed  around  the  entire  pupillary  mar- 
gin, and  the  iris  is  driven  forward,  the  disease  if  neglected  leads 
to  incurable  blindness. 

The  annular  adhesion  of  the  margin  of  the  iris  cannot  be 
broken  up  by  the  use  of  atropine,  and  all  internal  medication, 
including  mercurials  which  were  formerly  often  employed,  has 
proved  wholly  inefficacious  against  this  disease.  Iridectomy  is 
the  only  means  by  which  to  check  this  destructive  process. 

It  was  formerly  thought  that  the  operation  should  be  restricted 
to  those  cases  in  which  the  pupil  is  entirely  closed,  and  that  its 
only  benefit  was  to  provide  a  new  opening  for  the  admission  of 
light.     Von  Graefe,*  however,  demonstrated  the  great  value  of 

*  Arch.  f.  Ophth.,  B.  ii.  2,  pag.  202. 


338  •         IRIDO-CHOROIDITIS. 

the  operation  in  those  cases  also  in  which  the  pupil  remains  trans- 
parent, and  proved  that  it  is  the  only  means  by  which  to  check 
the  ruinous  course  of  the  disease.  Iridectomy  is  always  urgently 
indicated  so  soon  as  the  margin  of  the  pupil  becomes  completely 
adherent  to  the  lens,  even  though  good  vision  may  still  remain. 
Nothing  is  gained  by  waiting,  for  the  operation  will  have  to  be 
performed  later  and  under  less  favorable  circumstances.  In  gen- 
eral, with  irido-choroiditis,  the  longer  the  disease  has  lasted  the 
less  is  to  be  expected  from  iridectomy.  If  it  has  lasted  but  a 
short  time,  a  good  result  may  be  expected  from  the  operation,  even 
though  vision  has  already  become  quite  poor,  especially  when  the 
loss  of  vision  can  be  sufficiently  explained  from  the  condition  of 
the  pupil  and  the  clouding  of  the  cornea. 

But  if  a  disproportion  exist  between  the  transparency  of  the 
refracting  media  and  the  degree  of  vision,  so  that  there  is,  for 
instance,  a  distinct  red  reflex  from  the  fundus  upon  ophthalmo- 
scopic illumination,  while  the  patient  is  unable  to  count  fingers, 
or  if  defects  exist  in  the  visual  field,  no  essential  improvement  can 
be  expected  from  an  iridectomy.  A  very  guarded  prognosis  should 
also  be  given  in  those  cases  in  which  cataract  has  developed.  In 
such  there  is  generally  at  the  same  time  an  abnormal  softness  of 
the  eye,  indicating  a  slight  degree  of  atrophy.  Under  these  circum- 
stances, even  though  there  may  be  good  perception  of  light,  there 
can  usually  be  but  very  little  done,  since  generally  there  is  opacity 
of  the  vitreous  body,  as  well  as  of  the  lens,  and  the  retina  too  is 
proljably  somewhat  affected. 

Calcification  of  the  lens  frequently  happens  in  very  old  cases  of 
irido-choroiditis.  The  pupil  then  appears  of  a  chalky-white  or 
of  a  bright-gray  color  when,  as  is  often  the  case,  there  is  some 
fluid  witiiin  the  capsule  in  front  of  the  chalky  concrement.  In 
such  cases  the  iris  is  much  atrophied  and  closely  adherent  to  the 
calcified  lens.  This  being  so,  even  when  there  is  good  perception 
of  light,  there  can  be  very  little  hope  of  improvement  from  an 
operation. 

The  great  danger  connected  with  complete  adhesion  of  the  mar- 
gin of  the  pupil  often  makes  it  advisable  to  perform  an  operation 
in  cases  where  a  very  small  portion  of  the  margin  still  remains 
free.  This  free  portion  is  generally  that  vertically  above  the 
pupil,  and  it  is  best  to  perform  the  iridectomy  just  here.     If  at 


CORELYSIS.  389 

the  same  time  the  pupillary  region  be  clouded  by  the  products  of 
iritis,  or  be  optically  useless  from  other  causes,  as,  for  instance, 
from  corneal  opacities,  and  it  be  consequently  desirable  to  obtain 
at  the  same  time  some  optical  advantage  from  an  iridectomy  per- 
formed above,  it  must  be  determined  with  certainty  whether  the 
upper  lid  is  generally  sufficiently  raised  to  allow  the  new-formed 
pupil  to  be  of  any  use. 

Where  the  annular  adhesions  are  strong  and  have  existed  a  long 
time,  it  is  best  in  the  operation  of  iridectomy  to  forego  the  attempt 
to  break  through  them,  for  there  is  great  danger,  during  the  effort, 
of  rupturing  the  capsule  of  the  lens.  After  opening  the  anterior 
chamber  with  the  lance  knife,  the  iris  should  be  grasped  with  the 
forceps  at  a  little  distance  from  its  pupillary  margin,  and  then  toi'n 
through  in  its  continuity  by  traction,  while  the  pupillary  margin 
which  has  grown  fast  with  the  capsule  of  the  lens  is  left  behind. 

When  the  periphery  of  the  iris  is  irregularly  driven  forward,  a 
point  should  be  chosen  for  the  iridectomy  where  there  is  the  most 
room  for  the  lance  between  the  cornea  and  iris.  But  in  all  cases, 
even  where  the  anterior  chamber  is  very  shallow,  it  is  better  to 
make  the  incision  with  the  lance  than  with  the  ordinary  narrow 
cataract  knife.  The  wound  made  by  the  cataract  knife,  on  account 
of  the  steepness  of  its  walls,  shows  much  less  tendency  to  close 
like  a  valve,  from  the  simple  pressure  of  its  edges,  than  does  the 
flat  wound  made  by  the  lance.  This  fact  may  be  very  important 
in  the  not  infrequent  cases  in  which  liquefaction  of  the  vitreous 
and  defect  in  the  zonula  co-exist.  In  such  cases  a  slow  escape  of 
the  vitreous,  complete  collapse  and  final  atrophy  of  the  eye  must 
necessarily  follow  a  wound  so  made  as  to  gape  too  easily. 

Various  methods  of  operation,  under  the  name  of  "corelysis," 
have  been  proposed,  all  with  the  object  of  tearing  through  the 
adhesions  between  the  iris  and  the  capsule  of  tiie  lens.  The  great 
objection  to  this  operation  is  that  there  are  no  sufficient  indications 
for  its  performance.  Isolated  synechise  furnish  no  ground  for 
operation.  Their  influence  in  causing  relapses  has  been  greatly 
over-estimated.  In  rare  cases,  isolated  synechise  cause  annoyances 
which  have  been  called  "Iridalgia,"  and  which,  as  shown  by  a 
case  published  by   Hasner,*  may   be   relieved  by  corelysis.     If 

*  Prager  Vierteljahrschrift,  1862. 


340  ,  SYPHILITIC    lEITIS. 

annular  adhesion  of  the  pupillary  margin  have  formed,  and  tiie 
periphery  of  the  iris  be  driven  forward,  an  iridectomy  is  the 
most  certain  operation.  There  remain  only  those  cases  in  wiiich 
there  are  numerous  synechise  with  only  a  small  portion  of  the 
pupillary  margin  left  free.  Now,  this  condition  may  continue  for 
years  without  leading  to  any  bad  consequences.  But  in  the  case 
of  such  patients  as  cannot  at  any  desired  time  obtain  operative 
help  it  is  greatly  for  their  interest  to  avert  any  possible  danger. 
Of  course,  under  these  circumstances,  an  operation  having  for  its 
object  to  establish  a  circular  movable  pupil  is  to  be  preferred  to 
iridectomy,  but  in  just  these  cases  very  imperfect  resuUs  are  often 
obtained  from  corelysis. 

Streatfeild,*  who  was  the  first  to  practise  the  operation  method- 
ically, opened  the  anterior  chamber  by  a  wound  just  large  enongh 
to  admit  a  flat,  l>lunt  hook,  which  he  pushed  under  the  margin  of 
the  pupih  Weberf  toi'e  the  adhesions  in  a  similar  way  by  means 
of  a  blunt  hook.  Passavant|  advised  to  make  a  puncture  at  the 
margin  of  the  cornea,  to  grasp  the  iris  with  the  forceps  at  the 
margin,  where  it  is  attached  to  the  lens,  and  to  detach  it  by  gentle 
traction.  In  order  to  avoid  the  occurrence  of  anterior  synechise 
as  a  result  of  tlie  operation,  it  is  best  to  make  the  puncture  in  the 
transparent  portion  of  the  cornea,  and  not  too  near  the  margin. 

Iritis  syphilitica  is  one  of  the  earliest  symptoms  of  secondary 
syphilis,  and  is  generally  observed  simultaneously  with  condylo- 
mata or  with  syphilitic  roseola. 

The  great  majority  of  cases  of  iritis  which  are  observed  simul- 
taneously with  other  syphilitic  symptoms  are  distinguished  by  no 
anatomical  characteristics  from  idiopathic  iritis.  It  is  only  excep- 
tionally that  certain  formations  appear  in  the  iris  which  must  be 
regarded  as  the  specific  results  of  syphilis.  Formerly  they  were 
generally  called  condylomata,  till  Virchow§.  decided,  from  the 
clinical  history  of  these  formations,  that  they  ought  to  be  regarded 
as  gummy  tumors.     A  case  examined  anatomically  by  Colberg|| 

*  Ophth.  Hosp.  Rep.,  i.  pag.  6,  and  ii.  pag.  309. 

t  Arch.  f.  Ophth.,  B.  vii.  1. 

i  Ibid.,  B.  XV.  1,  pag.  259. 

§  Arch.  f.  path.  Anat.,  B.  xv.  pag.  306. 

11  Arch.  f.  Ophth.,  B.  viii.  1,  pag.  292. 


SYPHILITIC    IRITIS.  341 

fully  confirmed  this  view.  These  formations  grow  from  the  tissue 
of  the  iris,  generally  near  the  margin  of  tlie  pupil,  and  ajipear  at 
first  simply  as  a  swelling  of  the  parenchyma  itself.  Gradually 
the  small  tumor  rounds  up  in  the  form  of  a  pale-yellow  or  yel- 
lowish-red, translucent  nodule,  more  or  less  distinctly  permeated 
by  blood-vessels.  Simultaneously  the  signs  of  iritis  are  present 
(iritis  gummosa).  Under  proper  treatment  these  gummata  shrink 
away  rapidly,  drawing  themselves  back  into  the  tissue  of  the  iris, 
leaving  no  trace,  or  a  merely  discolored  spot. 

Often,  howevei',  these  tumors  grow  unchecked,  so  that  they 
almost  or  entirely  fill  the  anterior  chamber.  The  cornea  and 
neighboring  sclera  are  pushed  forward,  and  finally  break  through. 
Simultaneously  the  iritis  becomes  very  severe,  assumes  a  purulent 
character,  so  that  hypopion  occurs,  and  the  final  result  is  generally 
atrophy  of  the  eye.  It  is  only  very  seldom  that  gummata  of  the 
iris  occur  without  syphilis. 

Those  cases  of  syphilitic  iritis  in  which  no  gummata  are  present 
often  differ  in  their  clinical  history  from  the  idiopathic  form. 
Both  eyes  are  more  frequently  affected,  although  they  are  not 
always  attacked  at  exactly  the  same  time;  the  inflammation  is 
more  subject  to  relapses,  and  finally  there  come  on  more  fre- 
quently, especially  at  uight,  severe  ciliary  pains,  which  differ 
from  those  of  idiopathic  iritis  in  the  fact  that  they  do  not  corre- 
spond to  the  intensity  of  the  inflammatory  symptoms. 

The  prognosis  in  syphilitic  iritis  is  generally  scarcely  less  favor- 
able than  in  the  idiopathic  form ;  still,  it  is  to  be  remembered  that 
complications  with  a  peculiar  kind  of  faint  clouding  of  the  vitre- 
ous or  with  retinitis  or  choroiditis  occur.  The  gummata  of  the 
iris,  so  long  as  they  remain  small,  are  not  really  dangerous,  but 
where  their  growth  is  rapid  they  become  very  alarming. 

In  the  treatment,  atropine  mydriasis  is  under  all  circumstances 
absolutely  necessary.  In  iritis  gummosa,  an  energetic  general 
mercurial  treatment  should  in  most  cases  be  resorted  to,  though 
in  cases  where  neither  the  iritis  itself  nor  the  other  syphilitic 
symptoms  are  of  a  very  threatening  character  the  indications  for 
general  treatment  are  less  decided. 

Variola  and  recurring  fever  are  also  constitutional  diseases 
which  stand  in  evident  relation  with  iritis. 

In  both  cases,  however,  the  condition  is  generally  that  of  an 


342  HYDROMENINGITIS. 

inflannnatory  process  affecting  the  entire  uveal  tract  and  partici- 
pated in  by  the  iris.  In  these  cases,  therefore,  opacities  of  the 
vitreous  are  generally  simultaneously  present.  Iritis  also  occurs 
in  connection  with  articular  rheumatism,  especially  in  those  forms 
which  appear  to  stand  in  connection  with  gonorrhoea. 

Iritis  serosa,  or  hydroineningitis,  are  names  usually  given  to 
that  form  of  iritis  in  which  there  is  a  very  peculiar  participation 
on  the  part  of  the  membrane  of  Descemet.  In  addition  to  the 
symptoms  of  iritis  already  mentioned,  which,  moreover,  are  as 
apt  to  be  present  with  a  moderate  as  with  a  violent  inflammation, 
there  appear  on  the  posterior  surface  of  the  cornea  a  greater  or 
less  number  of  fine  gray  punctations,  the  largest  being  of  a  dirty- 
white  color.  Microscopic  examination  shows  that  they  are  due 
to  changes  in  the  epithelium  of  the  membrane  of  Descemet.  In 
an  eye  enucleated  on  account  of  irido-choroiditis  I  found  upon 
the  epithelial  surface  of  the  membrane  of  Descemet  numerous 
gray-white  prominences  so  loosely  attached  that  a  drop  of  water 
allowed  to  flow  over  it  was  sufficient  to  float  away  many  of  them. 
The  particles  which  floated  off  consisted  of  detritus  and  fat,  while 
the  spots  remaining  on  the  membrane  consisted  of  cells,  prolifer- 
ating and  undergoing  decomposition.  Similar  changes  were  going 
on  in  the  epithelium  about  these  specks,  the  process  extending 
even  to  the  cellular  elements  upon  the  ligamentum  pectinatum. 
Now,  since  this  structure  sinks  into  the  anterior  part  of  the  ciliary 
body,  it  may  be  easily  understood  how  the  epithelium  upon  the 
membrane  of  Descemet  may  become  affected  by  an  extension  of 
disease  from  the  choroid,  without  any  participation  by  the  iris. 
For  instance,  in  a  case  of  recent  choroiditis  and  retinitis  in  the 
region  of  the  macula  lutea,  with  slight  opacity  of  the  vitreous,  I 
saw  at  the  same  time  a  distinct  though  slight  punctated  appear- 
ance upon  the  membrane  of  Descemet.  It  disappeared  under 
atropine  treatment,  after  about  eight  days,  no  signs  of  iritis  having 
developed. 

Cases  of  iritis  which  present  these  changes  upon  the  membrane 
*  of  Descemet  are  generally  very  obstinate,  greatly  inclined  to  re- 
lapses, and  frequently  exist  in  both  eyes  at  the  same  time. 

The  treatment  is  the  same  as  in  other  forms  of  iritis.  Atten- 
tion must  be  paid  to  the  general  condition,  and,  above  all  things. 


SECOXDARY    IRITIS.  343 

atropine  is  necessary.     Derivatives  are  specially  suitable,  such  as 
vesications  upon  the  neck,  or  small  setons  upon  the  temple. 

Secondary  iritis  not  infrequently  occurs  as  a  consequence  of 
inflammatory  processes  in  the  collateral  vascular  channels. 

Frequently  both  the  primary  inflammation  and  the  secondary 
iritis  are  so  severe  that  hypopion  occurs  just  as  in  idiopathic  ii-itis. 

In  this  class  belong  many  cases  of  keratitis.  Purulent  keratitis, 
for  instance,  with  hypopion,  is  generally  accompanied  by  iritis, 
which  may  assume  a  purulent  character.  Atropine  and  luke- 
warm fomentations  are  the  flrst  remedies  to  be  resorted  to  in 
these  cases.  If  they  prove  insufficient,  it  is  often  possible  to 
check  the  process  by  an  iridectomy.  The  tissue  of  the  iris  is  gen- 
erally found  very  brittle,  and  its  surface  covered  with  a  layer  of 
exudation. 

Xearly  all  cases  of  acute  choroiditis  cause  secondary  iritis. 
This  is  true  both  where  the  disease  is  acute  and  violent,  leading 
rapidly  to  blindness,  and  in  those  more  chronic  cases  during  which 
acute  exacerbations  occur. 

Iritis  also  generally  follows  sooner  or  later  after  detachments 
of  the  retina. 

Frequently  iritis  is  caused  by  the  development  of  cataract, 
which  in  its  turn  is  due  to  choroidal  disease.  In  such  cataracts, 
even  in  old  people,  there  is  considerable  swelling  of  the  cortical 
substance.  The  iris  is  driven  forward,  moves  sluggishly  upon 
the  surface  of  the  lens,  and  soon  the  symptoms  of  iritis  appear. 
It  is  best,  therefore,  when  the  lens  swells  in  this  manner,  to  use 
atropine  as  soon  as  the  iris  appears  to  be  driven  forward. 

Tho!^e  forms  of  iritis  in  which  the  posterior  synechiae  are  not 
limited  to  the  pa{)illary  margin,  but  where  the  adhesions  between 
the  iris  and  the  capsule  of  the  lens  extend  far  back  toward  the 
periphery,  are  all  of  a  very  dangerous  nature. 

The  existence  of  extensive  adhesions  between  the  lens  and  the 
posterior  surface  of  the  iris  may  be  assumed  M'hen,  in  the  absence 
of  atropine  mydriasis,  the  entire  pupillary  margin  is  adherent, 
and  yet  the  periphery  of  the  iris  is  not  driven  forward,  or  the 
pupillary  margin  not  sunken  like  a  crater.  Under  such  circum- 
stances there  occurs  generally  a  disturbance  in  the  nutrition  of 
the  vitreous,  which  is  manifested  by  a  diffuse  or  flocculent  clouding 


344  SYNECHIA.       IllIDO-CYCLITIS. 

and  liquefaction  within  it,  as  M^ell  as  by  an  abnormal  softness  of 
the  eye.     Opacity  of  the  lens  generally  follows. 

This  form  of  iritis,  with  extensive  superficial  adhesions,  may 
develop  from  the  above  named  cases  of  annular  adhesion  of  the 
pupillary  margin,  by  an  absorption  of  the  fiuid  collected  behind 
the  iris;  but  cases  also  occur  which  run  a  rapid  course,  and  in 
which,  without  any  preceding  accumulation  of  fluid,  the  adhesions 
form  immediately  from  the  margin  of  the  pupil  to  the  periphery 
of  the  iris. 
•  In  many  cases  the  process  is  not  limited  to  a  simple  adhesion 
between  the  capsule  of  the  lens  and  the  uveal  layer,  but  the  cel- 
lular elements  participate  in  an  active  process  of  ])roliferation, 
forming  a  new,  thick,  vascularized  membrane,  which  extends  from 
the  uveal  layer  of  the  iris  over  upon  the  ciliary  body,  where  the 
same  iuflammatory  process  develops.  As  soon  as  the  ciliary  body 
is  involved  in  the  process  the  disease  is  called  irido-cyclitis. 

Spontaneous  irido-cyclitis  occurs  very  rarely,  but  when  it  does 
the  danger  to  the  eye  affected,  and  to  tiie  other  from  symj)athetic 
disease,  is  just  as  great  as  in  the  traumatic  form,  yet  to  be  described. 
The  pupil  is  either  contracted  or  closed  by  an  exudate.  If  the 
iris  be  naturally  of  a  bright  color,  its  surface  is  frequently  dotted 
wnth  a  number  of  dark-brown  specks,  which  upon  anatomical  ex- 
amination I  have  found  to  be  due  to  a  circumscribed  atropliy  of 
the  stroma,  which  allows  the  pigment  of  the  uveal  layer  to  be 
seen  through  it.     . 

The  cornea  appears  small  and  flat,  less  transparent  than  normal, 
the  anterior  chaml)er  shallow,  the  iris  and  lens  driven  forward. 
At  a  later  stage  the  new  membrane,  which  forms  upon  the  uveal 
layer  of  the  iris,  extends  directly  over  upon  the  ciliary  body. 
Certain  portions  of  the  periphery  of  the  iris  may  be  drawn  back 
toward  the  ciliary  body  by  the  shrinkage  of  the  new-formed  tissue, 
although  the  pupillary  part  is  driven  forward.  Frequently  at  the 
same  time  blood-vessels  may  be  recognized  upon  the  iris.  Proba- 
bly they  are  small  veins  which  are  distended  in  consequence  of  the 
obstructed  flow  of  blood  through  the  ciliary  part,  or  they  may  be 
more  distinct  by  reason  of  the  atrophy  of  tissue  upon  the  surface 
of  the  iris. 

The  most  important  symptom  of  disease  of  the  ciliary  body  is 
pain  upon  pressure  made  over  it,  especially  at  its  upper  portion. 


SYMPATHETIC    IRIDO-CYCLITIS.  345 

In  connection  with  the  symptoms  above  described  and  the  abnor- 
mal softness  of  the  eye,  yet  to  be  referred  to,  this  tenderness  of 
the  ciliary  body  is  a  very  important  symptom  for  the  diagnosis  of 
irido-cyclitis;  but  by  itself  no  importance  is  to  be  attached  to  it, 
since  the  same  symptom  frequently  occurs  in  connection  with  acute 
inflammation  of  the  cornea,  of  the  iris,  or  even  of  the  choroid. 

With  irido-cyclitis  there  never  fails  to  be  a  disturbance  in  the 
nutrition  of  the  vitreous  body.  It  frequently  occurs  at  a  very 
early  stage  of  the  disease,  and  is  manifested  by  an  abnormal  soft- 
ness of  the  eyeball.  At  a  later  stage,  opacities  of  the  lens  generally 
develop. 

Vision  is,  of  course,  always  gi'eatly  diminished,  and  may  finally 
be  lost  when  atrophy  of  the  eye  begins, 

Irido-cyclitis  may  develop  without  any  apparent  cause,  or  it 
may  follow  upon  other  forms  of  iritis.  It  is  most  frequently 
caused  by  wounds  of  the  eyeball.  In  such  cases,  however,  the 
appearances  in  the  disease  are  somewhat  modified  by  the  immediate 
consequences  of  the  injury. 

In  these  cases  the  proper  diagnosis  is  of  the  greatest  importance 
on  account  of  the  great  inclination  to  sympathetic  aifection  of  the 
other  eye.  Under  these  circumstances  the  most  important  prog- 
nostic symptom  is  a  tenderness  of  the  ciliary  body,  out  of  propor- 
tion to  the  external  inflammatory  signs,  while  at  the  same  time  it 
is  associated  with  a  diminished  tension  of  the  eyeball. 

The  conditions  for  the  occurrence  and  course  of  sympathetic 
irido-cyclitis  were  first  faithfully  described  by  Mackenzie.* 

After  one  eye  has  become  seriously  diseased,  or  is  already 
blinded,  generally  from  some  traumatic  cause,  the  signs  of  sym- 
})athetic  affection  of  the  second  eye  are,  as  a  rule,  first  manifested 
by  indistinct  vision.  Soon  the  signs  of  iritis  appear,  namely, 
pericorneal  injection,  ditfuse  clouding  of  the  cornea,  discoloration 
of  the  iris,  and  adhesions  with  the  capsule  of  the  lens.  The 
periphery  of  the  iris  may  at  first  be  driven  forward  by  the 
accumulation  of  fluid  behind  it.  Generally,  however,  extensive 
adhesions  of  its  posterior  surface  occur.  There  is  contraction  or 
absolute  closure  of  the  pupil,  with  shallowness  of  the  anterior 
chamber,  and  all  the  signs  of  irido-cyclitis.     A  diffuse  clouding 

*  Practical  Treatise  on  the  Diseases  of  the  Eye,  London,  1854,  pag.  64. 

23 


346  SYMPATHETIC    lEIDO-CYCLTTIS. 

of  the  vitreous  is  frequently  present  from  the  very  first,  which  ex- 
plains why  in  these  cases  it  is  that  at  the  beginning  of  the  inflam- 
mation, vision  is  much  poorer  and  the  ophthalmoscopic  image  much 
less  distinct  than  would  be  supposed  from  the  condition  of  the  re- 
fracting media,  as  examined  by  focal  illumination.  Later,  the  lens 
generally  becomes  opaque. 

The  tension  of  the  eyeball  may  increase  somewhat  at  first,  but 
later  there  ensues  a  distinct  and  permanent  diminution  of  tension. 

The  subjective  symptoms,  such  as  pain  and  photophobia,  are  in 
some  cases  severe,  but  generally  are  slight. 

Under  all  circumstances  the  course  of  the  disease  is  very  slow, 
with  perhaps  many  exacerbations.  Finally,  the  process  ends  with 
more  or  less  diminished  vision,  or  the  tension  of  the  eyeball  may 
continue  growing  constantly  less  till  there  is  complete  atrophy. 

The  wounds  which  are  followed  by  irido-cyclitis  of  the  injured 
eye  and  by  sympathetic  disease  of  the  other,  are  generally  lacer- 
ating or  penetrating  wounds.  A  foreign  body,  such  as  a  splinter 
of  iron  or  piece  of  percussion-cap,  may  or  may  not  have  been  left 
in  the  eye.  '  Simply  a  severe  blow  may  be  followed  by  like  results. 
Mackenzie  has  called  attention  to  the  fact  that  wounds  at  the 
junction  of  the  sclera  with  the  cornea  involving  the  ciliary  body 
are  the  most  dangerous,  especially  when  at  the  same  time  a  pro- 
lapse of  the  iris  occurs,  wiiich,  healing  in  the  wound,  is  subjected 
to  continuous  irritation  by  the  subsequent  contraction  of  the  cica- 
trix. 

Operations  on  the  eye  rarely  cause  sympathetic  inflammation  : 
still,  Critchett*  mentions  two  cases  in  which  it  followed  the  ex- 
traction of  cataract  by  the  flap  incision,  and  I,  too,  have  seen  one 
such  case  occur  in  Von  Graefe's  practice. 

This  sad  result  has  been  more  frequent  after  iridodesis,  an 
operation  which  involves  all  those  conditions  which  Mackenzie 
has  described  as  particularly  dangerous.  The  wound  is  at  the 
corneo-scleral  boundary,  there  is  prolapse  of  the  iris,  and  scar 
tissue  forms  in  such  a  way  that  the  portion  of  iris  within  the 
eye  is  subjected  to  continuous  traction. 

As  a  rule,  the  injured  eye  is  already  blind  before  it  causes  sym- 
pathetic disease  in  the  other,  but  Mackenzie  mentions  one  case  in 

*  Klin.  Monatsbl.,  i.  pag.  445. 


SYMPATHETIC    OCULAR    DISEASES.  347 

which  the  eye  first  affected  still  retained  some  power  of  vision, 
while  the  one  affected  by  sympathetic  disease  was  absolutely  lost. 

Between  the  primary  injury  and  the  appearance  of  the  sympa- 
thetic inflammation  there  is  generally,  as  Mackenzie  stated,  an 
interval  of  from  four  to  six  weeks.  This  appears  to  be  the  earliest 
time  at  which  sympathetic  disease  can  occur,  but  by  no  means  the 
latest.  So  long  as  there  remains  any  trace  of  irido-cyclitis,  with 
tenderness  of  the  ciliary  body  in  the  injured  eye,  there  is  reason 
to  fear  sympathetic  disease  of  the  other.  Moreover,  the  trau- 
matic inflammation  may  run  its  course  without  affecting  the  other 
eye;  the  injured  eye  may  become  atrophic  and  remain  for  years 
unchanged,  when  suddenly,  without  any  apparent  cause,  there 
appears  new  inflammation,  and  with  it  the  renewed  danger  of 
sympathetic  disease. 

This  is  most  to  be  feared  when  a  foreign  body  has  remained  in 
the  eye,  or  when  ossification  of  the  choroid  or  calcification  of  the 
lens  has  occurred. 

That  the  propagation  of  the  disease  from  one  eye  to  the  other 
takes  place  through  the  medium  "of  the  nerves  cannot  be  doubted. 
Formerly  this  was  thought  to  occur  in  the  course  of  the  optic 
nerve,  but  Arlt,*  in  1855,  showed  that  the  ciliary  nerves  are 
more  probably  the  ones  concerned.  Somewhat  later  H.  Miillerf 
exjiressed  the  same  view,  which  was  greatly  strengthened  by  the 
anatomical  investigations  of  De  Maats.|  Moreover,  Bowman§ 
has  pointed  out  the  very  frequent  beginning  of  the  sympathetic 
inflammation  at  a  point  exactly  symmetrical  with  that  of  the 
injury  in  the  first  eye.  This  goes  to  show  a  participation  of  the 
ciliary  nerves  in  the  process. 

It  may  then  be  regarded  as  certain  that  the  disease  is  propa- 
gated along  the  course  of  the  ciliary  nerves,  but  since  these  nerves 
contain  fibres  having  different  functions,  it  remains  doubtful  which 
set  of  fibres  is  concerned ;  there  appears  reason  to  suspect  the 
sensitive  fibres  of  the  fifth  pair.  It  should  be  noticed,  however, 
tiiat  this  sympathetic  disease  is  not  propagated  with  the  same 
rapidity  along  the  course  of  the  nerves  as  are  ordinary  irritations. 

*  Krankheiten  des  Auges,  1855,  i.  pag.  51. 
f  Arch.  f.  Ophth.,  B.  iv.  1,  pug.  368. 
J  Utrecht,  1865. 
§  Cf.  De  Maats,  1.  c,  pug.  53. 


348  ENUCLEATIOISr    OF    THE    EYE. 

Treatment. — When  the  occurrence  of  sympathetic  disease  first 
attracted  the  general  attention  of  ophthahnologists,  it  was  natural 
that  the  limits  of  the  subject  should  have  been  too  widely  ex- 
tended, and  this  fact  may  explain  the  brilliant  results  described 
as  having  followed  the  extirpation  of  the  primarily  diseased  eye. 
In  the  course  of  time,  however,  as  the  nature  of  sympathetic  irido- 
cyclitis became  better  understood,  the  conviction  grew  more  gen- 
eral that  the  extirpation  of  the  primarily  diseased  eye  cannot  allay 
a  sympathetic  inflammation  once  excited  in  the  other.  Critchett* 
was  the  fiript  to  make  the  valuable  suggestion  that  the  injured  eye 
be  extirpated  before  any  signs  of  inflammation  appear  in  the  other. 
Undoubtedly  the  enucleation  should  be  performed  as  soon  as  an 
eye,  whether  injured  or  not,  becomes  blind,  with  the  symj^toms  of 
irido-choroiditis,  loses  its  normal  consistency,  and  remains  painful 
upon  light  pressure  in  the  region  of  the  ciliary  body.  By  follow- 
ing this  rule  it  is  possible  that  many  eyes  may  be  unnecessarily 
extirpated,  since  all  the  recognizable  conditions  for  the  occurrence 
of  sympathetic  inflammation  may  be  present  without  its  following. 
Nevertheless,  the  sacrifice  of  a  blind,  shrunken,  and  disfigured 
eye  is  of  no  importance  as  comi)ared  with  the  danger  of  complete 
blindness,  which  will  be  caused  by  the  appearance  of  sympathetic 
irido-cyclitis  in  the  other  eye. 

On  the  other  hand,  however,  the  enucleation  must  be  resorted 
to  with  more  hesitation  when  irido-cyclitis  does  not  exist.  The 
depressing  influence  which  the  extirpation,  even  of  a  blind  eye, 
has  upon  the  patient  is  generally  very  considerable,  and  under 
these  circumstances  an  artificial  eye  does  not  always  effect  a 
cosmetic  improvement. 

When  irido-cyclitis  has  once  appeared,  the  question  arises 
whether  at  this  late  period  it  is  still  advisable  to  remove  the 
eye  first  diseased.  The  hope  formerly  cherished,  of  being  able 
by  this  operation  to  arrest  the  sympathetic  inflammation,  must 
be  relinquished  ;  nevertheless  there  is  always  the  possibility  that, 
after  tiie  removal  of  the  cause  of  the  disease,  the  sympathetic 
process  may  run  a  more  favorable  course  than  if  the  cause  re- 
mained. If  under  these  circumstances  there  still  remain  in  the 
injured  eye  some  degree  of  vision,  which  of  course  it  is  desirable 

*  Klin.  Monatsbl.,  i.  pag.  447. 


IRIDECTOMY.  349 

to  retain,  the  enucleation  must  be  postponed,  as  the  benefit  of 
the  operation  is  very  problematical,  and  there  is  no  justification 
for  sacrificing  an  actual  though  slight  degree  of  vision. 

Nor  can  any  more  benefit  be  expected  from  the  operation  for 
the  eye  affected  with  sympathetic  inflammation.  Iridectomy, 
which  for  a  long  time  was  greatly  over-estimated  as  a  cure  for  all 
kinds  of  iritis  and  irido-choroiditis,  proves  wholly  useless  in  irido- 
cyclitis. 

Critchett*  was  the  first  to  assert  that  in  irido-cyclitis  all  opera- 
tive interference  so  long  as  any  inflammation  remains  is  absolutely 
hurtful.  He  therefore  advised  to  limit  the  treatment  to  protec- 
tion from  all  injurious  influences,  and  to  await  the  disappearance 
of  all  inflammatory  symptoms.  This  may  require  a  number  of 
months,  and  meanwhile  absolute  atrophy  of  the  eye  may  occur; 
but  nevertheless  no  better  result  is  obtained  by  too  early  operative 
interference. 

Even  when  all  irritability  and  tenderness  has  disappeared  from 
the  eye  an  iridectomy  does  not  generally  prove  sufficient,  since 
the  adhesion  of  the  uveal  layer  with  the  capsule  of  the  lens  is  too 
strong.  Only  that  part  of  the  stroma  which  is  grasped  by  the  for- 
ceps can  be  torn  away.  The  uveal  layer  and  the  false  meml)rane 
connected  with  it  remain  behind,  a  hemorrhage  in  the  anterior 
chamber  generally  follows,  and  the  result  is  that  no  improvement 
is  obtained.  Critchett  therefore  adopted  the  advice  previously 
given  by  Von  Graefe,t  to  extract  the  lens  at  the  same  time  when 
making  the  iridectomy,  in  those  cases  of  irido-cyclitis  in  which 
the  pupil  is  closed  by  false  membrane  or  in  which  there  is  opacity 
of  the  lens. 

The  best  method  for  these  cases  is  the  peripheral  linear  incision, 
to  be  made  just  as  long  as  for  cataract  extraction. 

If  the  anterior  chamber  be  shallow,  the  narrow  knife  is  passed 
through  the  iris  and  false  membrane,  and  behind  them,  till  the 
counter-punction  is  made.  A  pair  of  straight  forceps  is  then 
inserted  in  such  a  way  that  one  branch  is  before  and  the  other 
behind  the  iris ;  but  even  then,  on  account  of  the  strength  of  the 
adhesions,  it  is  generally  not  possible  to  draw  out  of  the  wound 
that  portion  of  the  iris  which  is  grasped  by  the  forceps,  but  it  is 

*  Klin.  Monatsbl.,  i.  pag.  440.  f  Arch.  f.  Ophth.,  B.  vi.  2,  pag.  97. 


350  SYMPATHETIC    OCULAR    DISEASES. 

necessary  to  introduce  a  fine  pair  of  scissors,  just  as  were  the 
forceps,  with  one  point  before  and  the  other  behind  the  iris,  in 
order  to  cut  through  it,  in  the  direction  of  a  radius,  to  the  pupil. 
The  flap  of  iris  so  formed  may  then  generally  be  drawn  out  of 
the  wound  and  completely  removed. 

During  this  procedure  a  portion  of  the  cortical  substance  of  the 
lens  generally  flows  out.  The  remainder  of  the  lens  is  then  to 
be  removed,  either  by  rubbing  and  pressing  on  the  cornea  or  by 
introducing  a  spoon. 

It  cannot  be  doubted  that  less  destructive  cases  of  iritis  may 
occur  as  sympathetic  inflammation,  and  if  properly  treated  may 
run  a  favorable  course.  Still,  upon  critically  examining  such 
cases,  it  is  often  very  difficult  to  determine  whether  there  really 
is  any  causal  connection  between  the  diseases  in  the  two  eyes,  or 
whether  their  simultaneous  occurrence  is  merely  accidental. 

The  most  convincing  proof  of  the  sympathetic  nature  of  a  dis- 
ease of  the  eye  is  given  when,  immediately  after  the  extirpation 
of  the  eye  first  diseased,  the  affection  disappears  from  the  other, 
as,  for  instance,  in  the  form  of  blepharospasm  mentioned  on 
page  230,  which  was  proved  by  Donders  to  be  sym})athetic.  It 
is  only  exceptionally  that  these  reflex  neuroses  attain  such  a  grade 
as  that  there  described,  where  the  blepharospasm  destroyed  the 
usefulness  of  an  otherwise  normal  eye.  In  the  majority  of  cases 
there  exists  only  a  painful  irritation  of  the  eye.  Photophobia, 
subjective  sensations  of  light,  slight  lachrymation  and  redden- 
ing of  the  eyes  upon  slight  use,  inability  to  work  continuously, 
transitory  darkness  of  the  visual  field,  etc.,  may  exist  a  long  time 
without  the  occurrence  of  actual  inflammation.  The  rapid  disap- 
pearance of  these  syjnptoms  after  the  extirpation  is  proof  of  their 
sympathetic  character. 

If  the  effect  of  the  operation  be  slower,  appearing  only  after 
several  weeks,  as,  for  instance,  in  certain  cases  where  there  is  con- 
traction of  the  visual  field,  which  may  be  regarded  as  due  to  sym- 
pathetic disease,  the  proof  that  it  is  so  can  be  furnished  only  by  the 
accumulation  of  numerous  observations.  If,  however,  the  enuclea- 
tion have  no  effect  upon  the  disease  in  the  other  eye,  we  must  look 
about  for  other  proofs  of  the  sympathetic  nature  of  the  disease. 

The  view  frequently  expressed,  that  the  condition  of  the  eye 
affected  with  sympathetic  disease  is  directly  dependent  upon  the 


SYMPATHETIC   OCULAR   DISEASES.  351 

condition  at  that  particular  time  of  the  eye  primarily  affected, 
that  every  exacerbation  in  the  last  is  responded  to  by  an  exacer- 
bation in  the  first,  is  by  no  means  confirmed  by  observation. 

If,  however,  following  certain  determined  changes  in  one  eye, 
we  see  a  distinctly  characterized  disease  of  the  other  eye,  which 
without  some  such  cause  occurs  very  rarely,  the  cumulative  evi- 
dence of  such  cases  proves  their  sympathetic  character.  This,  for 
instance,  is  the  case  in  irido-cyclitis  sympathetica. 

It  is  very  difficult  in  observing  any  particular  case  to  be  con- 
vinced of  its  sympathetic  character.  For  instance,  the  case  of 
choroideo-retinitis  described  by  Von  Graefe,*  which  I  know  per- 
fectly well,  since  I  observed  it  with  him,  presented  such  a  peculiar 
ap[)earance  that  Von  Graefe  regarded  its  sympathetic  nature  as 
probable.  But  it  requires  a  number  of  such  cases  to  furnish 
satisfactory  proof  of  the  correctness  of  such  an  opinion. 

If,  on  the.other  hand,  the  disease  of  the  second  eye  be  attended 
with  symptoms  by  no  means  peculiar,  and  if  the  condition  be  one 
which  we  see  occur  under  the  most  varied  circumstances,  only 
very  careful  investigation  and  a  great  number  of  cases  could 
establish  the  sympathetic  nature  of  the  affection. 

The  only  disease  which  can  positively  be  said  to  cause  sympa- 
thetic inflammation  is  irido-cyclitis.  All  other  statements  on  the 
subject,  as,  for  instance,  that  after  operation  for  glaucoma  in  one 
eye  sympathetic  glaucomatous  inflammation  may  occur  in  the 
other,  must  be  regarded  as  based  on  little  more  than  assumptions. 

If  a  few  days  after  iridectomy  in  one  eye  an  acute  glaucomatous 
inflammation  appear  in  the  other,  this  accident  certainly  may  be  a 
very  unpleasant  surprise ;  but  the  circumstance  that  the  operation 
in  the  first  eye  and  the  inflammation  in  the  second  occur  only  a 
few  days  apart  argues  against  the  suspicion  of  a  sympathetic  con- 
nection. For  in  ocular  inflammations  whose  sympathetic  origin 
is  demonstrated,  it  is  not  days  but  weeks  before  the  inflammatory 
process  proceeding  from  one  eye,  and  following  the  course  of  the 
ciliary  nerves,  reaches  the  second. 

Furthermore,  glaucoma  is  a  bilateral  disease  in  so  great  a 
majority  of  cases  that  it  is  no  wonder  if,  after  iridectomy  in  one 
eye,  glaucomatous  inflammation  appear  in  the  other.     It  is  to  be 

*  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  171. 


352  ENUCLEATION   OF   THE    EYE. 

remembered,  too,  that  attacks  of  glaucoma  are  greatly  favored  by 
loss  of  sleep,  mental  anxiety,  etc.,  and  that  the  operation  furnishes 
cause  for  just  these  conditions  in  very  many  patients. 

It  is  finally  to  be  mentioned  that  some  cases  have  been  observed 
in  which  the  use  of  an  artificial  eye  caused  sympathetic  disease. 
Lawson*  mentions  a  case  in  which,  five  years  previously,  an  eye 
had  become  blind  and  atrophic,  in  consequence  of  ulceration  of 
the  cornea.  Daring  all  this  time  it  had  shown  no  annoying- 
symptoms,  but  by  using  an  artificial  eye  it  became  inflamed  and 
painful,  and  finally  caused  sympathetic  irido-cyclitis.  Lawson 
explained  this  intolerance  of  an  artificial  eye  by  the  fact  that  a 
portion  of  the  corneal  tissue,  too  sensitive  to  endure  the  friction 
of  a  foreign  body,  still  remained  upon  the  shrunken  stump. 

Salomonf  reports  a  case  in  which  symptoms  of  sympathetic 
irritation,  which  were  the  occasion  for  the  enucleation  of  an  eye, 
reappeared  when  an  artificial  eye  was  inserted.  Sucli  a  case  may 
be  explained  by  supposing  that  the  disease  excited  along  the  course 
of  the  ciliary  nerves  still  persisted  after  the  enucleation  of  the 
eye,  and  that  the  portions  of  the  ciliary  nerves  remaining  in  the 
orbit  being  irritated  by  the  presence  of  the  artificial  eye,  the  sym- 
pathetic disease  reappeared  in  the  other  eye. 

Enucleation  is  performed  in  the  following  manner.  The  lids 
are  held  apart  by  the  speculum ;  the  conjunctiva  is  grasped  at  the 
upper  part  of  the  eye  with  the  fixation  forceps,  is  cut  close  about 
the  cornea  and  immediately  loosened  from  the  sclera  by  strokes 
of  the  scissors,  carried  far  back  toward  the  equator ;  the  rectus 
superior  is  then  caught  with  the  strabismus  hook  and  its  scleral 
insertion  divided  ;  the  same  is  done  with  the  other  recti  muscles. 
When  these  four  muscles  are  divided,  it  is  best  to  remove  the 
speculum  and  by  pressure  directed  backward  upon  the  margin  of 
the  lids  to  dislocate  the  eyeball  forward.  Should  the  conjunctival 
wound  prove  too  small  to  allow  the  eyeball  to  pass  through,  it 
must  be  somewhat  enlarged.  When  the  eyeball  has  passed  through 
the  conjunctival  wound  and  is  pressed  forward  between  the  mar- 
gins of  the  lid,  a  pair  of  curved  scissors  is  to  be  introduced  at  the 
inner  angle  of  the  eye  and  the  optic  nerve  divided.     The  eye  may 

*  Ophth.  Hosp.  Rep.,  vi.  2,  pug.  123. 

I  Dublin  Quarterly  Journal,  xxxv.,  pag.  58. 


IRIDEREMIA.       COLOBOMA.       TUMORS.  353 

then  be  easily  drawn  out  of  the  orbit,  the  two  oblique  muscles  cut 
oft'  at  their  insertion,  and  the  enucleation  ended.  It  is  well  after 
the  bleeding  ceases  to  close  the  conjunctival  wound  with  a  suture, 
passing  the  thread  alternately  in  and  out  near  the  margin  of  the 
conjunctiva  around  the  entire  wound,  and  then  drawing  it  up, 
like  a  tobacco-pouch,  and  tying  it. 

Remnants  of  the  foetal  pupillary  membrane  (membrana  pupil- 
laris  perseverans)  are  frequently  observed  in  the  form  of  a  greater 
or  less  number  of  isolated  or  anastomosing  threads,  springing 
from  the  circulus  minor  iridis,  extending  across  the  margin  of  the 
pupil,  and  ending  either  upon  the  capsule  of  the  lens  or  upon  a 
pigmented  disc  occupying  the  centre  of  the  puj)il,  or  they  may 
pass  uninterruptedly  across  the  pupil.  Under  these  circumstances 
the  margin  of  the  pupil  retains  its  motility. 

Irideremia,  or  absence  of  the  iris,  occurs  very  rarely  as  a  con- 
genital defect,  either  with  or  without  other  congenital  anomalies. 

Traumatic  irideremia,  the  tearing  of  the  iris  from  the  ciliary 
body,  happens  only  in  consequence  of  some  severe  injury,  and  is 
therefore  generally  complicated  with  loss  of  vision,  due  to  hemor- 
rhages in  the  vitreous,  etc.  It  is  only  exceptionally  that  these 
complicating  injuries  are  unimportant,  but  when  they  are,  recovery 
with  good  vision  is  possible.  It  is  noticeable  that  the  secretion 
of  the  aqueous  humor  is  not  affected  by  the  total  loss  of  the  iris, 
and  that  a  normal  power  of  accommodation  may  remain. 

Ammon  describes  a  case  in  which,  in  consequence  of  a  severe 
shock  to  the  head,  in  a  case  of  suicide  by  shooting,  the  lens  was 
displaced  and  the  iris  reflected  behind  the  ciliary  body. 

A  congenital  opening  in  the  iris  (coloboma  iridis)  occurs  either 
in  only  one  eye,  more  frequently  the  left,  or  in  both  eyes  at  the 
same  time.  The  fissure  is  generally  below  or  directed  inward 
and  downward.  It  generally  causes  no  particular  disturbance  of 
vision  if  not  connected  with  other  abnormities.  Frequently  there 
are  simultaneously  corresponding  defects  in  the  choroid. 

Tumors  of  the  iris,  aside  from  the  gummy  tumors  already  men- 
tioned, occur  but  rarely.  Among  the  different  varieties  which  have 
been  observed  are  congenital  pigment  tumors,  granulation  tumors, 
telangiectasise  and  melanosarcoma  of  the  iris. 


.354  TUMORS    OF    THE    IRIS. 

Cysts  of  the  iris  are  generally  caused  by  wounds.  In  37  cases 
collected  by  Rothmund,*  28  had  been  preceded  by  wounds,  and 
in  most  of  these  there  had  been  perforation  of  the  cornea.  The 
contents  of  these  cysts  may  be  either  serous  or  colloidj  or  even  of  a 
more  solid  consistency.  Their  walls  are  sometimes  very  delicate 
and  transparent,  in  other  cases  they  are  thicker  and  more  opaque. 
These  cysts  are  situated  either  in  the  tissue  proper  of  the  iris  or 
they  appear  as  a  new  growth  upon  its  surface.  In  a  case  observed 
by  White  Cooper,  the  cyst  was  connected  with  the  ciliary  body. 

The  removal  of  a  cyst  is  iudicated  so  soon  as  the  diagnosis  is 
certain,  for  its  continued  presence  and  constant  growth  may  cause 
consecutive  iritis,  ulceration  of  the  cornea,  and  possibly,  as  in  a 
case  observed  by  Hiilke,t  sympathetic  irritation  of  tlie  other  eye. 
The  best  method  is  to  open  the  anterior  chamber  with  the  lance 
knife,  near  the  cyst,  and,  if  possible,  without  wounding  its  walls. 
The  cyst  then  often  protrudes  of  itself  through  the  wound  in  the 
cornea,  or  it  may  be  drawn  out  with  a  spoon  or  hook.  If  any 
])ortion  of  the  cyst  wall  be  left  in  the  eye,  or  if  the  cyst  be  merely 
punctured,  it  will  often  reappear. 

A  peculiar  tumor  of  the  iris  is  sometimes  caused  by  eyelashes, 
which  penetrate  the  anterior  chamber  at  the  time  of  a  wound 
in  the  cornea.  After  remaining  there  some  time,  they  cause  the 
development  of  growths  which  greatly  resemble  atheroma,  being 
Mhitish  in  color,  circumscribed  in  form,  and  filled  with  a  pasty 
substance  containing  fat  and  cholesterin.  I  observed  one  such 
case  in  which  about  six  cilia  penetrated  the  anterior  chamber 
tiu'ough  a  perforating  wound.  Three  months  later,  two  white 
dots  were  noticed,  for  the  first  time,  upon  the  iris.  After  the 
removal  of  the  cilia  from  the  anterior  chamber  the  little  tumors 
continued  to  grow,  and  six  months  after  the  injury,  their  extir- 
pation seemed  advisable.  The  larger  tumor  had  now  attained 
a  diameter  of  1|  mm.  It  was  spherical,  and  sat  upon  the  iris 
like  a  ball  attached  by  only  a  small  pedicle.  Its  surface  had  a 
pearly,  glistening,  semi-transparent  appearance,  and  within  it  was 
an  opaque,  white  nucleus,  from  |^  to  f  mm.  in  diameter.  The 
smaller  tumor  was  of  a  similar  character.     Both  were  removed 


*  Klin.  Monatshl.  f.  Augenheilk.,  1872,  pag.  189. 

f  On  Cysts  in  the  Iris,  Ophth.  Hosp.  Kep.,  vi.  pag.  12. 


TUMORS    OF    THE    IRIS.  355 

by  an  iridectomy.  Prof.  W.  Krause,  of  G5ttingen,  kindly  made 
a  microscopic  examination,  and  gave  me  the  following  report : 
'•The  central  white  nucleus  contained  free  fat  in  larger  and  smaller 
drops,  numerous  crystals,  mostly  cholesterin,  and  polygonal  cells. 
The  transparent,  peripheral  part,  aside  from  a  few  cholesterin 
crystal^,  consisted  of  long,  hexagonal,  slightly  flattened,  epidermis 
cells,  destitute  of  nuclei.  A  thick  layer  of  similar  cells  formed 
the  cortical  part.  This  layer  at  the  base  of  the  tumor  is  covered 
with  a  thin,  indistinct,  fibrous,  connective-tissue  membrane,  which, 
however,  does  not  completely  envelop  the  tumor,  but  leaves  the 
layer  of  cells  exposed  at  several  places.  An  epithelial  covering 
can  nowhere  be  discovered  upon  this  connective-tissue  membrane, 
which,  moreover,  at  the  base  of  the  tumor,  is  continuous  with  the 
tissue  of  the  anterior  surface  of  the  iris.  As  explaining  these  re- 
markable growths,  we  may  suppose  that,  at  the  time  of  the  injury, 
fat-producing  cells,  probably  from  the  hair  follicles,  were  carried 
with  the  cilia  into  the  iris,  and  that  their  growth  was  continued 
there.  The  mass  of  new-formed  cells  resemble  those  found  in 
atheroma." 


DISEASES  OF  THE  LENS. 


We  have  already  had  occasion,  on  page  26,  to  mention  that 
the  physiological  growth  and  nutrition  of  the  lens  cause  changes 
whose  dioptrical  consequences  alFect  refraction  and  accommoda- 
tion. In  this  place  we  have  to  do  principally  with  the  catoptric 
phenomena  caused  by  the  senile  changes  of  the  lens.  The  greater 
density  assumed  by  the  lens  causes  the  difference  between  the 
index  of  refraction  of  the  lens  on  the  one  hand,  and  of  the  aque- 
ous humor  and  vitreous  body  on  the  other,  to  become  greater. 
At  the  limits  of  these  media,  accordingly,  a  greater  reflection  of 
light  takes  place,  w'hich  causes  a  noticeable  gray  shimmer  in  the 
pupil.  This  gray  reflex  from  the  pupil  becomes  still  more  strik- 
ing from  the  fact  that  frequently  the  fibres  of  the  lens  assume  an 
index  of  refraction  somewhat  different  from  that  of  its  amorplious 
substance.  The  structure  of  the  anterior  cortical  layer  becomes, 
therefore,  more  distinctly  visible  by  focal  illumination  than  in 
the  normal  condition ;  certain  sectors  appear  of  a  dull-gray  color, 
so  that  one  may  think  he  has  before  him  a  cataractous  opacity, 
while  a  single  glance  with  the  ophthalmoscope  suffices  to  ])rove 
the  transparency  of  the  lens. 

No  annoyances  are  connected  with  this  condition  aside  from  the 
contraction  of  the  range  of  accommodation,  and  a  slight  diminu- 
tion of  vision. 

With  reference  to  the  prognosis,  it  is  to  be  remarked  that  this 
senile  condition  of  the  lens  may  remain  unchanged  many  years 
without  the  development  of  cataract. 

The  many  forms  of  cataract  may  be  most  simply  divided  into 
progressive,  or  such  as  eventually  cause  opacity  of  the  entire  lens, 
and  partial  or  stationary  opacities.  This  indeed  does  not  give  an 
absolutely  sharp  division,  since  the  total  opacities  of  the  lens  are 
at  first  partial,  and,  moreover,  there  are  partial  opacities  respect- 
ing which  it  cannot  be  foretold  whether  they  will  develop  to  total 
opacities  or  not,  or  which  go  on  in  this  process  of  development 
with  extreme  slowness. 
35G 


SOFT    CORTICAL   CATARACT.  357 

The  physiological  relations  of  the  lens  exercise  a  great  influence 
upon  the  form  of  the  cataract.  In  total  opacities  of  the  lens  in 
young  individuals,  the  tendency  to  soften  and  liquefy  preponderates, 
while  in  more  advanced  age  these  processes,  it  is  true,  may  occur, 
but  they  are  always  limited  to  the  cortical  part,  while  the  nucleus 
of  the  lens  has  already  become  hard  and  resists  the  softening  ])rocess. 

The  softening  of  the  cortical  substance  manifests  itself  by  the 
appearance  of  a  number  of  light-gray,  radiating,  transparent 
strijies,  perhaps  0.5  to  0.75  mm.  in  breadth,  dividing  the  cor- 
tical substance  into  several  pearly,  glistening  sectors.  The  cortical 
substance,  however,  still  remains  transparent,  so  that,  with  the 
pupil  dilated  and  by  focal  illumination,  one  may  look  deep  into 
the  lens,  in  order  to  satisfy  himself  whether  its  whole  substance  be 
softened,  or  whether  a  hard  nucleus  still  exist.  The  fact,  already 
mentioned,  that  the  physiological  growth  and  nutrition  of  the  lens 
cause  a  gradual  hardening  of  the  nucleus,  furnishes  the  ground 
upon  which  to  suspect  the  existence  of  a  hard  nucleus  in  all  cata- 
racts which  develop  after  the  thirtieth  year  of  life,  even  although, 
when  examined  by  focal  illumination,  the  differences  in  color  be- 
tween the  hard  and  the  soft  forms  niay  be  so  slight  as  to  leave  the 
matter  doubtful.  In  old  age  the  color  of  the  nucleus  of  the  lens 
generally  makes  it  distinctly  visible. 

The  soft  cortical  cataract  generally  develops  so  much  the  more 
rapidly  the  broader  the  sectors  into  which  the  corticalis  is  divided ; 
there  is  generally  at  the  same  time  a  swelling  of  the  clouded  lens; 
the  anterior  capsule  appears  very  convex;  the  iris  is  pressed  for- 
ward, and  impeded  in  its  movements. 

The  swelling  of  the  lens  gradually  recedes,  by  the  absorption 
on  the  part  of  the  aqueous  humor  of  a  portion  of  the  fluid 
enclosed  in  the  capsule. 

In  the  further  course  of  the  process  there  may  be  either  a 
thickening  or  a  complete  liquefaction  of  the  softened  corticalis. 

In  the  latter  case  the  cataract  assumes  a  uniform  milky  appear- 
ance, and  only  here  and  there  can  fine  white  spots  and  flakes  be 
seen  attached  to  the  capsule. 

If  this  liquefaction  occur  in  childhood,  and  if  the  cataract  re- 
main a  long  time  uninterfered  with,  a  very  considerable  reduction 
in  the  volume  of  the  lens  may  occur,  so  that  the  cataract  recedes 
from  the  plane  of  the  pupil. 


358  MORGAGNIAN    AND    NUCLEAR    CATARACT. 

It  may  even  happen  that  the  lens  shrinks  to  a  thin  layer  of 
precipitates  upon  the  inner  surface  of  the  capsule,  and  so  assumes 
exactly  the  appearance  of  a  secondary  cataract. 

Even  in  old  age  an  absolute  liquefaction  of  the  corticalis  is  pos- 
sible; still,  there  is  accompanying  it  no  reduction  in  the  size  of 
the  lens,  or  one  exceeding  very  little  the  physiological  reduction. 
Moreover,  there  always  remains  the  hard  nucleus  of  the  lens,  which 
sinks  to  the  bottom  of  the  fluid  with  which  the  capsule  is  filled, 
whatever  may  be  the  position  in  which  the  patient  holds  his  head 
(cataracta  Morgagniana).  The  diagnosis  of  this  form  of  cataract 
is  easy  if  the  capsule  has  remained  transparent.  By  the  help  of 
focal  illumination,  with  the  pupil  moderately  dilated,  one  can  see 
the  yellowish  nucleus  of  the  lens  whose  sinking  proves  the  lique- 
faction of  the  corticalis.  On  the  contrary,  if  the  capsule  has  be- 
come opaque  by  deposits  upon  its  inner  surface  (capsular  cataract), 
and  if  the  pupil  can  be  only  partially  dilated  by  atropine,  as  is  so 
often  the  case  in  old  people,  the  diagnosis  may  be  exceedingly 
difficult. 

It  still  remains  to  be  mentioned  that  the  prognosis  of  an  opera- 
tion in  cataracta  Morgagniana  is  generally  regarded — though  per- 
haps erroneously — as  less  favorable  than  in  the  usual  forms  of 
senile  cataract.. 

Relatively  less  frequent  than  the  soft  cortical  cataract  are  those 
cloudings  of  the  lens  which  begin  by  a  hardening  and  a  distinct 
demarcation  of  the  nucleus  from  the  cortical  substance.  The 
nuclear  cataract  never  develops  until  an  age  in  which  the  nucleus 
has  become  markedly  differentiated  from  the  cortical  substance, — 
that  is,  seldom  before  the  thirtieth,  and  generally  about  the  fiftieth 
year.  In  their  mildest  grades,  these  changes  present  a  process 
similar  to  that  which  we  have  already  described  as  the  senile 
change  of  the  lens,  only  they  are  limited  to  the  nucleus.  By 
diffuse  daylight  the  pupil  shows  a  striking  gray  reflex,  which, 
however,  as  appears  immediately  by  focal  illumination,  has  its 
seat  not  in  the  superficial  layers,  but  in  the  deeper  })art  of  the 
lens.  The  nucleus  is  distinctly  differentiated  from  the  cortical 
substance,  upon  ophthalmoscopic  illumination,  by  means  of  a 
weak  reflecting  mirror.  According  to  the  position  in  which  the 
mirror  is  held,  one  sees  the  nucleus  bounded  u2:)on  the  one  side  by 


SENILE    CATARACT.  359 

a,  bright  reflex  and  on  the  other  by  a,  dark  shadow  of  the  corticalis, 
and  by  slight  movements  of  the  instrument  this  phenomenon  of 
refraction  may  be  caused  to  appear  at  different  points  successively 
all  around  the  nucleus.  The  nucleus,  however,  may  remain  a  long 
time  transparent.  These  changes  in  the  lens  cause,  in  the  first 
place,  an  increase  of  refraction;  still,  the  degree  of  the  myopia 
cannot  always  be  exactly  determined,  because  there  is  sinuilta- 
neously  a  diminution  of  vision,  due  partly  to  irregularity  of 
refraction  and  partly  to  a  decrease  of  transparency. 

This  condition  may  remain  stationary  a  long  time,  or  may  lead 
finally  to  actual  cataract  of  the  nucleus,  and  of  the  entire  lens. 
The  lens  assumes  more  and  more  a  gray  color,  becomes  gradually 
opaque,  and  finally  opacity  of  the  cortical  substance  develops. 

The  above  described  form  of  cataract  occurs  both  idiopathically, 
without  known  causes,  and  also  in  connection  with  other  ocular 
diseases;  it  is  especially  frequent  in  eyes  which  have  suftered 
from  glaucoma,  in  high  degrees  of  myopia,  and  where  there  have 
been  extensive  choroidal  changes,  for  instance  in  connection  with 
staphyloma  posticum. 

The  most  frequent  form  of  opacity  in  the  lens  is  the  so-called 
senile  cataract.  It  generally  begins  near  the  equator  of  the  lens, 
and,  according  to  Forster,*  with  a  clouding  of  that  layer  of  the 
corticalis  which  lies  immediately  upon  the  nucleus.  There  occur 
then  a  number  of  short  linear  opacities  or  irregular  cloudy  specks, 
which  appear  dark  by  ophthalmoscopic  illumination  and  gray  by 
focal  illumination.  They  gradually  increase  both  in  size  and  in 
number.  Simultaneously  the  nucleus  becomes  more  distinctly 
differentiated  from  the  corticalis,  by  a  more  or  less  decided  yellow- 
ish-brown color  ;  its  transparency,  however,  does  not  suffer  to  the 
same  degree  as  that  of  the  corticalis. 

The  anatomical  changes  occurring  in  the  corticalis  are  somewhat 
different  from  those  in  the  nucleus.  The  fibres  of  the  corticalis 
appear  finely  punctated,  and  run  more  or  less  together,  so  that 
in  the  layers  which  can  be  scaled  off  from  the  corticalis  one  can 
only  indistinctly  recognize  the  individual  fibres.  Besides  this  fine 
granular  punctation,  there  occurs  an  exudation  of  myeline  and 

*  Arch.  f.  Ophth.,  B.  iii.  2,  pag.  187. 


360  CONGENITAL    CATARACT. 

other  drops,  which  appear  red  under  the  microscope;  and,  finally, 
cholesterin  crystals  appear  in  cataracts  which  have  existed  a  long 
time,  especially  when  the  process  has  been  that  of  softening  of  the 
cortical  is. 

This  chemical  decomposition  appears  less  prominent  in  the 
nucleus.  On  the  contrary,  the  individual  fibres  appear  more 
consistent,  shrunken,  uneven  on  the  surface,  dry  and  brittle,  and, 
on  account  of  their  increased  opacity,  easier  to  recognize  than  in 
the  normal  condition.  The  nucleus  is  generally  so  much  the 
harder  and  larger  the  darker  it  is;  indeed,  cases  occur  in  which 
the  nucleus  is  so  large  and  dark  that,  when  examined  with  the 
naked  eye,  the  pupil  appears  black,  since  the  large  dark  nucleus 
leaves  but  little  space  for  the  semi-transparent  corticalis.  These 
cases  have  been  called  cataracta  nigra.  Their,  diagnosis  was  diffi- 
cult before  the  time  of  the  ophthalmoscope,  but  a  single  glance 
with  that  instrument,  or  by  focal  illumination,  suffices  to  make  the 
relations  clear.  In  some  such  cases,  upon  anatomical  examina- 
tion, I  found  the  nucleus  of  a  transparent  dark  red.  Microscopic 
examination  shows  that  the  dark  color  is  due  simply  to  a  delicate 
red  tinge  of  each  individual  fibre,  and  that  the  dark  tinge  was 
caused  by  many  of  these  lying  in  apposition.  Pigment  molecules 
were  not  present,  either  in  or  about  the  fibres  of  the  lens.  The 
yellowish  or  brownish  color  of  the  lens,  so  frequent  in  senile 
cataract,  is  caused  in  exactly  the  same  way. 

Senile  cataract  is  called  "  ripe"  when  the  opacity  has  extended 
to  the  external  cortical  layers.  This  condition  is  in  general  de- 
sirable, but  by  no  means  necessary  for  operation.  In  old,  so-called 
over-ripe  senile  cataracts  the  lens  is  generally  somewhat  flattened 
by  the  shrinking  of  its  fibres.  They  experience  simultaneously 
in  the  anterior  cortical  substance,  changes  which  will  be  more 
particularly  described  under  the  head  of  capsular  cataract. 

Cataract  may  develop  at  any  age,  even  during  foetal  life.  Both 
partial  and  total  cataract  occur  congenitally.  In  one  case  I 
found  an  emulsive  detritus  of  fibres  which  had  been  already 
formed,  and  a  great  number  of  fatty  granular  cells,  which  prob- 
ably consisted  of  a  detritus  of  the  embryonal  cells  destined  for 
the  formation  of  the  lens  fibres.  Frequently  there  is  congenital 
amblyopia  in  connection  with  congenital  cataract;  this  cannot  be 


CONGENITAL    CATAEACT,  ETC.  361 

detected  for  some  years,  until  the  child  has  attained  a  certain 
degree  of  mental  development.  The  hereditary  nature  of  con- 
genital cataract  is  often  observed ;  but  even  when  both  parents 
have  normal  eyes  it  frequently  happens  that  several  of  their 
children  are  born  with  cataract,  while  other  brothers  and  sisters 
remain  free.  Once,  indeed,  at  a  twin  birth,  I  have  seen  one  twin 
affected  with  cataract  while  the  other  had  healthy  eyes. 

Furthermore,  the  various  forms  of  cataract  may  develop  during 
childhood,  and  in  view  of  the  possibility  of  co-existing  amblyopia, 
may  present  the  greatest  diagnostic  difficulties.  If  nystagmus 
be  also  present,  one  may  conclude  that  amblyopia  exists  with  the 
cataract.  The  hereditary  nature  of  cataract  developed  later  in 
life  has  been  proved. 

In  diabetes  mellitus  a  relation  is  known  to  exist  between  the  gen- 
eral condition  and  the  development  of  cataract.  In  a  case  which 
was  chemically  examined  by  L.  Carius,*  a  great  quantity  of  sugar 
was  detected  in  the  aqueous  humor,  and  it  probably  existed  in  the 
lens  and  vitreous  body.  Further  investigations  must  determine 
whether  this  is  the  real  cause  of  the  cataract.  The  oft-repeated 
statement  that  cataracta  diabetica  generally  develops  very  rapidly, 
I  have  not  found  true  in  cases  where  it  occurred  in  aged  persons. 

J.  Meierf  has  recently  observed  cataract  as  a  consequence  of 
ergotism,  and  Rothmund,!  a  case  in  connection  with  a  very  pe- 
culiar degeneration  of  the  skin.  '  In  most  cases  of  uncomplicated 
cataract  a  determinate  cause  cannot  be  ascertained.  It  can  only 
be  asserted  as  a  general  rule  that  the  frequency  of  cataract  is  in 
direct  relation  with  the  increase  of  age. 

As  a  direct  and  immediate  cause  of  cataract  all  wounds  of  the 
lens  are  to  be  named  (cataracta  traumatica).  The  presence  of 
entozoa  in  the  human  lens  is  one  of  the  greatest  rarities. 

Among  those  causes  of  cataract  which  have  their  seat  in  the  eye 
itself,  we  know  accurately  only  those  which  at  the  same  time  are 
deleterious  to  vision.  Among  these  belong,  for  instance,  certain 
cases  of  iritis,  especially  those  complicated  with  cyclitis  or  choroidi- 
tis, also  certain  forms  of  choroiditis,  either  with  or  without  disease 
of  the  vitreous,  and  especially  retinal  detachment  and  glaucoma. 


*  Klin.  Monatsbl.,  1863,  pag.  172. 

t  Arch,  f,  Opbth.,  B.  viii.  2,  pag.  120.  j  Ibid.,  B.  xiv.  1,  pag.  157. 

24 


362  TESTING   VISION. 

The  diagnosis  of  complicated  cataract  is  generally  not  difficult. 
There  are  either  evident  changes  in  the  iris  or  in  the  cornea,  or 
the  cataract  itself  shows  certain  peculiarities.  But  even  when  all 
other  evident  changes  are  absent,  the  presence  of  a  complicating 
disturbance  of  vision  can  generally  be  determined  by  carefully 
testing  the  perception  of  light. 

In  order  to  determine  accurately  the  degree  of  vision  in  cataract, 
care  should  be  taken  that  no  diffuse  light,  but  only  that  from  a 
flame,  reaches  the  eye.  If  the  examination  be  made  by  daylight, 
the  j)atient  is  to  be  placed  with  his  back  toward  the  window  and 
the  light  not  allowed  to  fall  into  his  eyes  from  the  side.  Even 
when  thert  is  total  clouding  of  the  lens,  fingers  can  often  be 
counted  at  the  distance  of  some  inches  from  the  eyes^  and  move- 
ments of  the  hand  recognized  at  the  distance  of  one  or  two  feet. 
If  the  field  of  vision  be  free,  so  that  movements  of  the  hand 
can  be  recognized  from  the  side  of  the  eye,  the  perception  of  light 
may  be  regarded  as  sufficient.  If  one  wish  to  make  a  very  exact 
examination,  it  is  best  to  do  it  in  a  dark  room,  with  only  a  single 
lamp,  and  to  proceed  as  above  described,  and  further,  by  lessening 
the  flame,  or  increasing  its  distance  from  the  eye,  to  determine 
the  smallest  quantity  of  light  whicli  the  patient  is  able  to  recog- 
nize. It  is  a  very  good  plan  to  place  the  lamp  behind  the  patient 
and  then  cast  the  flame  from  in  front  into  his  eye  by  means  of 
a  plane  mirror.  The  least  intensity  of  light  perceptible  to  the 
patient  may  be  determined  by  holding  the  mirror  at  a  greater 
distance  from  the  eye,  and  more  easily  than  when  the  lamp  is 
used  directly  as  the  source  of  light,  while  the  slightest  movement 
of  the  mirror  suffices  to  deflect  from  the  eye  the  reflected  rays. 

The  field  of  vision  is  tested  by  quickly  changing  the  position 
of  the  lamp  or  by  reflecting  its  flame,  with  the  mirror,  into  the 
eye  from  various  points  in  the  periphery  of  the  field.  In  both 
cases  the  patient  should  be  able  quickly  and  accurately  to  state 
the  position  of  the  light.  The  method  of  testing  vision  by  arti- 
ficial illumination  has  the  advantage  that  we  can  modify  the  inten- 
sity of  the  light,  and  is  therefore  the  one  to  be  employed  for  those 
cases  in  wdiich  there  is  reason  to  suspect  some  complicating  disease 
of  the  eye. 

Especial  care  and  attention  should  be  had  in  testing  the  per- 
ception of  light  in  the  soft  cortical  cataracts  of  young  individuals. 


PARTIAL    OPACITY    OF   THE    LENS.  363 

particularly  when  they  are  unilateral.  Complications  with  intra- 
ocular diseases,  such  as  detachment  of  the  retina  and  clouding  of 
the  vitreous,  are  relatively  much  more  frequent  under  these  cir- 
cumstances than  in  senile  cataract,  and  even  by  the  most  careful 
examination  it  is  not  always  possible  absolutely  to  exclude  the 
existence  of  complications.  Even  where  there  is  partial  opacity 
of  the  lens  it  may  under  certain  circumstances  be  very  difficult  to 
determine  whether  vision  stands  in  the  proper  relation  to  the 
degree  of  opacity  in  the  lens,  as  determined  ophthalmoscopically. 
It  is  of  great  importance  in  all  these  cases  to  test  the  field  of  vision. 

Among  the  partial  opacities  of  the  lens,  the  first  to  be  mentioned 
is  the  cataracta  incipiens, — that  is,  the  beginning  of  cortical  or 
nuclear  cataract.  One  frequently  finds,  as  an  accidental  ophthal- 
moscopic discovery,  linear  opacities  in  the  equatorial  part  of  the 
corticalis,  with  no  disturbance  of  vision;  the  latter  does  not  occur 
until  these  opacities  invade  the  region  of  the  pupil.  Under  these 
circumstances,  so  long  as  vision  is  sufficient  for  the  purposes  of 
the  individual,  it  is  best  not  to  inform  him  of  the  nature  of  his 
disease,  because  such  opacities  may  remain  for  years  without 
making  any  further  progress,  and  it  is  certainly  not  right,  if  their 
sight  is  at  present  good,  to  cause  anxiety  in  the  minds  of  patients 
with  reference  to  a  blindness  which  perhaps  may  never  occur,  or 
at  least  not  for  many  years.  Of  course  one  would  not  hesitate  to 
explain  the  nature  of  the  disease  to  patients  whose  vision  is  no 
longer  sufficient  for  the  demands  of  their  occupation. 

]More  rarely  cataracta  incipiens  occurs  with  a  quite  irregular 
flaky  clouding  of  the  anterior  corticalis,  immediately  below  the 
capsule.  In  such  cases  its  progress  is  generally  very  slow.  Com- 
plications with  choroiditis,  detachment  of  the  retina,  etc.,  exist 
in  many  but  by  no  means  all  of  these  cases. 

Frequently  there  develops  in  the  lens  a  great  number  of  fine 
points  or  irregular  lines,  between  which,  transparent  lens-substance 
remains  (cataracta  punctata  and  striata).  The  course  of  these  cases 
is  generally  very  slowly  progressive,  or  they  may  even  remain  a 
long  time  unchanged  in  a  condition  which  reduces  the  patient  to 
a  very  insufficient  degree  of  vision.  In  such  cases,  just  as  in  the 
very  slowly  progressive  nuclear  cataracts,  it  would  be  very  unwise 
to  postpone  operation  until  the  so-called  "  ripeness"  of  the  cata- 
ract,— that  is,  until  the  entire  lens  becomes  opaque.     Generally 


364  LAMELLAR    CATARACT. 

these  cataracts  are  ready  for  operation  much  earlier.  The  age 
of  the  patients  generally  makes  it  impossible  to  cause  resorption 
of  the  cataract  by  discision,  while,  on  the  other  hand,  in  the  oper- 
ation by  extraction,  there  is  the  fear  of  leaving  behind  transparent 
cortical  masses.  Frequently,  however,  the  unclouded,  or,  more 
properly  speaking,  the  ophthalmoscopically  transparent  cortical  is, 
gradually  becomes  hard  and  horn-like ;  in  the  operation  it  comes 
away  easily  and  completely  from  the  capsule. 

It  has  been  recommended,  when  the  cortical  is  appears  to  have 
retained  its  normal  consistence,  to  perform  discision  some  days 
before  extraction,  in  order  to  soften  the  corticalis  and  so  make  the 
extraction  easier. 

A  particularly  interesting  form  of  partial  lens  opacity  is  the 
lamellar  cataract.  Its  peculiarity  is,  that  between  a  transparent 
corticalis  and  a  likewise  transparent  nucleus  there  is  a  clouded 
layer  of  lens-substance.  Frequently  this  layer  has  upon  its  an- 
terior surface,  and  sometimes  too  on  its  posterior  surface,  a  num- 
ber of  white  points;  in  other  cases  the  entire  clouded  portion  is 
filled  with  radiating  lines.  Sometimes  similar  figures  or  irregular 
processes  extend  from  the  limits  of  the  opacity  into  the  trans- 
parent cortical  substance,  or  this  substance  itself  may  likewise 
be  clouded  in  a  diffuse,  punctated,  or  linear  manner.  Very  rarely 
cases  occur  in  which  several  layers  become  clouded,  while  between 
them  is  transparent  lens-substance. 

There  is  no  difficulty  in  the  diagnosis.  Upon  dilating  the  pupil, 
and  by  focal  illumination,  one  sees  behind  the  pupil  a  uniform 
opacity  whose  convex  surface  lies  perceptibly  at  some  distance  from 
the  plane  of  the  pupil,  and  is  separated  from  the  periphery  of  the 
lens  by  a  sharply  defined  boundary-line.  Generally  the  j)osterior 
limit  of  the  lamellar  cataract  can  be  recognized  through  the 
opacity  and  the  transparency  of  the  nucleus  at  the  same  time  be 
observed.  Upon  ojihthalmoscopic  illumination  the  entire  disc 
ap})ears  dark  and  sharply  defined.  But  when  illuminated  l)y 
light  falling  perpendicularly  upon  it,  and  when  the  opacity  is 
not  too  dense,  the  central  part  often  shows  the  red  reflex  from 
the  fundus,  which  also  proves  the  transparency  of  the  nucleus. 

E.  von  Jaeger,*  who  first  described  this  form  of  cataract  and 

*  Ueber  Staar- und  Staaroperationen,  Wien,  1854,  pag.  17  nnd  22. 


LAMELLAR   CATARACT.  365 

examined  it  anatomically,  explains  its  mode  of  occurrence  as  fol- 
lows. At  an  early  period  of  life,  when  the  lens  is  still  in  tiie  pro- 
cess of  rapid  growth,  from  some  cause  or  other  an  opacity  forms  in 
the  external  cortical  layers,  which,  however,  by  the  growth  of  new 
lens  fibres,  gradually  are  pushed  away  from  the  capsule.  AVhen 
these  new  lens  fibres  are  quite  normal,  the  corticalis  will  be  trans- 
parent; when  they  are  somewhat  diseased,  it  will  be  clouded,  in 
the  manner  above  described. 

Lamellar  cataract,  in  the  great  majority  of  cases,  occurs  in  both 
eyes  at  the  same  time.  Whether  it  often  occurs  congenitally  can- 
not with  certainty  be  stated,  since,  in  the  narrow  pupils  of  new-born 
children,  such  a  cataract  may  be  easily  overlooked.  The  develop- 
ment of  lamellar  cataract  in  childhood  has  been  proved  beyond 
doubt.  Arlt  and  Horner  regard  it  as  connected  with  convulsive 
brain  disturbances.  Horner,*  moreover,  calls  attention  to  the  coin- 
cidence of  a  peculiar  abnormity  of  the  teeth,  which  depends  upon  an 
imperfect  development  of  the  enamel  fibres  (the  so-called  rachitic 
teeth).  Von  Graefef  observed  the  occurrence  of  lamellar  opacities 
three  times,  in  lenses  dislocated  by  injury,  and  once  with  iritis. 

Finally,  we  must  mention  certain  rare  cases  of  partial  opacities 
which  ])enetrate  the  lens  in  the  direction  of  its  axis,  either  with 
or  without  simultaneous  lamellar  opacities.;!;  Moreover,  opacities 
of  the  nucleus  in  the  form  of  a  triangular  radiating  figure  are 
occasionally  observed. 

Lamellar  cataracts  generally  remain  absolutely  stationary.  Cases 
in  which  they  have  been  followed  by  a  shrinkage  of  the  entire  lens, 
or  where  calcification  of  the  clouded  layer  has  occurred,  are  among 
the  greatest  rarities.  § 

With  lamellar  cataract,  vision  is  in  inverse  relation  to  the  extent 
and  degree  of  opacity,  provided  there  be  no  congenital  amblyopia 
or  nystagmus.  Myopia,  as  Bonders  remarks,  frequently  exists  with 
lamellar  cataract. 

In  the  treatment  of  lamellar  cataract,  the  first  step  is  to  deter- 

*  Klin.  Monatsbl.,a86o,  pag.  181. 

t  Arch.  f.  Ophth.,  B.  ii.  1,  pag.  273;  B.  iii.  2,  pag.  373. 

X  Pilz,  Prager  Vierteljahrsschrift,  B.  xxv.  ;  Von  Ammon,  Zeitschrift  fiir 
Ophthalmologic,  B.  iii.  pag.  86,  unci  klinische  Darstellung,  etc.,  B.  iii.  pag.  67  ; 
E.  Miiller,  Arch.  f.  Ophth.,  B.  ii.  2,  pag.  169;  O.  Becker,  Bericht  iiber  die 
"Wiener  Augenklinik,  "Wien,  1867,  pag.  99. 

^  y.  Graefe,  Arch.  f.  Ophth.,  B.  iii.  2,  pag.  379. 


366  ANTERIOR   CENTRAL    CATARACT. 

mine  the  degree  of  vision.  Opacities  of  this  kind  occur  which  in- 
deed have  considerable  superficial  extent,  but  are  at  the  same  time 
so  thin  that  vision  is  not  greatly  reduced,  perhaps  not  more  than  by 
one-third  or  one-fourth.  Under  such  circumstances  it  would  not 
be  well  to  resort  to  operation.  If  the  lamellar  cataract  be  so  small 
that  it  encroaches  only  a  little  upon  the  region  of  the  pupil,  many 
of  these  patients  learn  in  the  interest  of  distinct  vision  to  shade  their 
best  eye  in  such  a  manner,  with  the  hand,  that  the  pupil  dilates 
and  a  part  of  the  unclouded  peripheral  zone  is  exposed.  In  such 
cases,  too,  atropine  mydriasis  causes  a  very  considerable  improve- 
ment in  vision.  The  continuous  use  of  atropine  may  be  allowed 
in  a  solution  so  graduated  that  the  pupil  is  not  dilated  ad  maxi- 
mum, but  only  so  widely  as  is  necessary  to  carry  it  beyond  the  l)or- 
der  of  the  cataract.  The  objection  made  in  this  connection,  that 
the  atropine  mydriasis  involves  a  paralysis  of  accommodation,  does 
not  amount  to  much,  since  if  the  solution  be  properly  graduated, 
paralysis  of  accommodation  above  a  certain  grade  may  be  avoided, 
and  in  any  event  the  accommodation  may  be  replaced  by  convex 
lenses.  The  operation  of  iridectomy  can  scarcely  be  expected  to 
cause  a  greater  improvement  in  vision  than  does  the  use  of  atropine- 
The  artificial  pupil  may  easily  prove  too  large  and  cause  dazzling 
and  indistinct  vision  by  enlarging  the  circles  of  diffusion.  At  any 
rate,  the  operation  of  iridotomy  (comp.  page  314)  is  a  better  one. 

The  most  favorable  optical  conditions  could  be  obtained  by  the 
operation  of  iridodesis  (comp.  page  321)  if  it  were  not  for  the 
danser  of  irido-cvclitis  connected  with  it. 

Lamellar  cataract  is  generally  so  large  that  only  a  narrow,  trans- 
parent, marginal  zone  exists,  or  even  this  may  be  diffusely  clouded. 
In  such  cases,  when  vision  is  greatly  reduced,  and  no  improvement 
can  be  attained  by  atropine,  the  removal  of  the  lens,  either  by 
discision  or  by  extraction,  is  indicated. 

Among  the  partial  opacities  of  the  lens  belong,  still  further, 
small  cataractous  spots  at  the  anterior  or  posterior  pole  of  the  lens. 

Cataracta  centralis  anterior  sometimes  occurs  congenitally,  and 
in  such  cases  almost  always  in  both  eyes.  It  develops  more  fre- 
quently in  children,  and  somewhat  rarely  in  adults,  in  consequence 
of  ulcers  which  cause  perforation   of  the  cornea.     Arlt's*  view, 

*  Die  Krankheiten  des  Auges,  B.  i.  pag.  232,  Prag,  1835. 


PYRAMIDAL  CATARACT.  367 

agreeing  with  the  then  existing  opinion  that  a  portion  of  the  ex- 
udate from  the  corneal  nicer  remained  attached  to  the  capsule,  does 
not  explain  the  connection.  I  have  satisfied  myself  that  corneal 
ulcers,  which  do  not  perforate  at  the  centre,  but  near  the  margin 
of  the  cornea,  may  cause  cataracta  centralis. 

The  contraction  of  the  pupil  after  the  escape  of  the  aqueous 
humor  allows  only  the  centre  of  the  anterior  capsule  to  come  in 
contact  with  the  posterior  surface  of  the  cornea,  and  this  alone 
seems  sufficient  to  induce  a  disturbance  of  nutrition  at  this  place 
on  the  lens. 

Frequently  the  central  opacity  is  elevated  in  the  form  of  a 
pyramid  above  the  surface  of  the  capsule ;  indeed,  cases  have 
been  observed  in  wiiich  a  thread-like  connection  existed  between 
the  posterior  surface  of  the  cornea  and  the  capsular  cataract. 
Cataracta  pyramidalis  also  occurs  congenitally,  but  it  generally 
develops  during  childhood. 

H.  Miiller*  was  the  first  who  showed  that  in  cataracta  pyra- 
midalis the  entire  opacity  is  situated  within  the  capsule.  In  the 
case  which  he  examined,  a  conical  elevation  sat  upon  the  anterior 
surface  of  the  lens,  at  about  its  middle;  its  base  was  nearly  round, 
and  had  a  diameter  of  about  3  mm,,  while  its  height  was  about 
1  mm.  The  surface  of  the  elevation  was  uneven,  and  its  color 
an  intense  white.  It  consisted  internally  of  a  chalky  mass.  The 
capsule  extended  over  it,  following  the  irregularities  of  its  surface. 

For  a  case  of  pyramidal  cataract,  which  I  examined  anatom- 
ically, I  must  thank  the  kindness  of  Dr.  Samelson,  of  Manchester. 
Itf  occurred  in  the  left  eye  of  an  individual  twenty-three  years 
old,  who  in  his  third  year  had  the  smallpox,  and  after  that  a  cen- 
tral corneal  opacity  and  this  cataract.  The  apex  of  the  pyramid 
appeared  nearly  to  touch  the  i)osterior  surface  of  the  cornea,  its 
base  rested  upon  a  sort  of  broad  pedestal,  which  had  an  uneven, 
wrinkled  surface  and  an  irregular  boundary.  ' 

The  cataract  was  removed  by  linear  extraction,  preserved  in 
spirits,  and  given  to  me  for  examination.  I  found  the  pyramid 
about  2  mm.  high,  and  its  base  about  1.5  mm.  in  diameter. 
Under  a  weak  magnifying  power  it  appeared  striped  by  a  great 


*  Verhandl.  der  physik.  med.  Gesellschaft  zu  AYih-zburg,  B.  vii.  pag.  288. 
t  Ophth.  Hosp.  Kep.,  v.  1,  pag.  48. 


368  PYRAMIDAL  CATARACT. 

number  of  fine  longitudinal  folds;  at  its  base  it  was  continuous 
with  a  wrinkled,  hyaloid  membrane,  which,  although  very  much 
thinned,  could  still,  by  the  evident  remains  of  the  intra-capsnlar 
cells,  be  recognized  as  the  anterior  capsule.  In  connection  witli  it 
there  was  a  thick  mass,  which,  under  a  strong  magnifying  power, 
appeared  striated  and  punctated.  It  cleared  up  with  dilute  acid, 
and  contained  distinct  traces  of  a  delicate,  hyaloid,  membranous 
growth,  together  with  cholesterin,  and  other  lance-shaped  crys- 
tals, which  are  frequently  found  in  the  secondary  altered  cata- 
ractous  lens-substance.  Upon  perpendicular  section  through  the 
dried  preparation,  the  pyramid,  from  base  to  apex,  appeared  to 
be  formed  of  delicate  lamellae,  arranged  parallel  to  the  surface  of 
the  lens,  showing  the  same  structure  as  capsular  cataract.  The 
lamellae  could  easily  be  torn  apart,  except  upon  the  smoooth  sur- 
face of  the  pyramid,  where  they  seemed  as  if  closely  united,  to 
form  a  delicate  membrane,  without,  however,  its  being  possible  to 
isolate  such  a  structure.  At  the  base  of  the  pyramid  was  a  fatty 
or  calcified  mass,  deeper  still  a  striated  tissue,  and  lastly  amor- 
phous masses,  the  detritus  of  the  cataractous  lens-substance. 

The  .capsule  could  not  be  recognized  upon  sections  of  the  dried 
preparation ;  it  must  have  become  torn  and  lost.  It  is  highly 
probable  that  the  pyramid  was  covered  by  the  very  much  thinned 
anterior  capsule.  If  the  pyramid  had  been  external  to  the  cap- 
sule, a  section  of  the  capsule  would  have  been  found  between  the 
base  of  the  pyramid  and  the  remains  of  the  cataractous  lens- 
substance,  since  at  this  place  it  could  not  have  been  accidentally 
lost  either  before  or  during  preparation. 

The  occurrence  of  pyramidal  cataract  may  be  explained  by 
supposing  that  at  an  early  period  of  life,  during  the  existence  of 
a  corneal  fistula,  an  adhesion  forms  between  the  inner  surface  of 
the  cornea  and  the  capsule  of  the  lens,  which,  when  the  cornea 
becomes  again  gradually  removed  from  the  lens,  is  drawn  out  to 
a  point. 

At  present  no  one  would  attempt  the  experiment,  formerly 
much  practised,  of  detaching  the  pyramidal  cataract  from  the 
anterior  surface  of  the  lens,  unless  he  meant  purposely  to  open 
the  capsule  and  cause  the  absorption  of  the  lens. 

In  general,  operative  interference  is  seldom  indicated  in  cata- 
racta  centralis,  since  there  is  generally  an  absolutely  transparent 


I 


CALCIFICATIO^-    OF    THE    LENS.  369 

portion  of  the  lens  between  the  opacity  and  the  margin  of  the 
puj)il.  If,  under  such  circumstances,  vision  do  not  seem  pro- 
portionate to  the  transparency  of  the  refracting  media,  no  im- 
provement can  be  expected  from  a  cataract  operation. 

Circumscribed  opacities  of  the  posterior  corticalis  always  awaken 
a  suspicion  of  a  complicating  disease  of  the  internal  membranes  of 
the  eye.  For  instance,  in  choroiditis  or  in  pigmentation  of  the 
retina,  radiating  and  often  feathered  strise  are  seen  converging 
toward  the  posterior  pole,  upon  the  posterior  surface  of  the  lens. 
AVith  dilatation  of  the  pupil  and  focal  illumination  the  opacity  in 
the  posterior  corticalis  and  the  transparency  of  the  anterior  portion 
of  the  lens  can  be  easily  demonstrated. 

Still  more  frequent  than  this  form  are  certain  small,  circum- 
scribed opacities,  which  develop  in  chronic  diseases  of  the  internal 
ocular  membranes,  in  the  region  of  the  posterior  pole  of  the  lens, 
and  therefore  are  called  cataracta  polaris  posterior.  They  are 
quite  frequent,  for  instance,  in  staphyloma  posticum  with  sec- 
ondary choroiditis.  In  many  cases  their  anatomical  position  is 
rather  within  the  vitreous  than  in  the  lens. 

Calcification  of  the  lens  occurs  most  frequently  in  complicated 
cataract,  and  begins  often  as  capsular  cataract,  which,  under  these 
conditions,  may  attain  a  very  considerable  development.  The 
chalky  deposits  (mostly  carbonate  of  lime)  appear  generally  as  a 
great  number  of  isolated  granules,  or  in  spherical  formations  com- 
posed of  concentric  layers.  When  the  lime  is  dissolved  by  acid,  an 
organic  substance  is  left  behind.  The  chalky  deposit  generally 
takes  place  immediately  upon  the  superficial  cataractous  layers  of 
the  lens.  A  shell  of  chalk  varying  in  thickness  is  formed  beneath 
the  capsule,  and  if  at  the  time  of  the  chalky  deposit  the  fibres  of 
the  lens  were  not  fully  dissolved,  their  form  may  be  preserved 
by  petrifaction  in  the  living  eye.  The  entire  lens  may  become  so 
calcified  that  it  is  transformed  into  a  stony  concretion,  which  is 
still  enclosed  in  an  atrophied  capsule. 

In  such  cases  there  is  generally  a  loosening  of  the  normal 
attachments  of  the  lens,  due  to  the  liquefaction  of  the  vitreous 
body  and  the  atrophy  of  the  zonula. 

Striking  oscillations  of  the  lens  can  be  seen  during  movements 
of  the  eye,  or  it  may  have  sunk  entirely  away  from  its  normal 
position.     If  the  lens  sink  into  the  anterior  chamber,  it  causes  a 


370  CATARACT   OPERATION. 

very  irritable  condition,  which  after  a  time  passes  over  into  in- 
flammation. When  the  lens  has  only  very  recently  fallen  into  the 
anterior  chamber,  it  is  generally  sufficient  to  dilate  the  pupil  with 
atropine,  and,  by  throwing  the  head  backward,  allow  the  chalk 
concrement  to  sink  back  into  the  vitreous  body.  If  this  do  not 
succeed,  the  extraction  of  the  calcified  lens  is  necessary. 

In  such  cases  the  lens  must  be  fixed  by  a  needle  thrust  into  its 
posterior  surface,  before  the  chamber  is  opened.  If  this  precau- 
tion be  omitted,  the  escape  of  the  aqueous  humor  allows  the  lens 
to  come  in  contact  with  the  cornea,  and  it  is  immediately  pushed 
back  through  the  pupil  and  disappears  in  the  vitreous  body. 

OPERATION  FOR  CATARACT. 

The  diiferent  methods  of  operating  on  cataract  have  for  their 
object  either  to  remove  the  entire  lens,  through  a  suitable  opening 
(extraction),  or,  by  splitting  the  anterior  capsule,  to  expose  the  lens 
to  the  action  of  the  aqueous  humor,  and  so  cause  its  absorption 
(discision). 

The  methods  by  which  the  lens  M^as  pushed  away  from  behind 
the  pupil  (reclination)  are  no  longer  ])ractised. 

Soft  cortical  cataracts,  in  which  the  entire  lens  has  become  con- 
verted into  a  thick  fluid  mass,  and  which  contain  no  hard  nucleus, 
may  often,  with  advantage,  be  extracted  through  a  linear  corneal 
wound. 

This  method  of  extraction  by  the  linear  incision  was  first  me- 
thodically practised  by  Gibson,  in  1811,  and  by  Travers,  in  1814. 
In  Germany  it  was  principally  practised  by  Friedrich  von  Jaeger 
for  capsular  cataract.  Yon  Graefe  preferred  it  to  all  others.  He 
opened  the  anterior  chamber  by  a  puncture  at  the  temporal  side 
of  the  cornea.  It  is  advisable  to  make  the  wound  upward,  in  view 
of  the  possibility  that  a  prolapse  of  the  iris  may  occur,  which  it  will 
be  necessary  to  remove.  The  lance  knife,  held  at  a  considerable 
angle  with  the  cornea,  and  still  in  such  a  way  that  the  capsule  of 
the  lens  will  not  be  wounded,  is  introduced  at  2  or  2.5  mm.  from 
the  margin  of  the  sclera,  and  the  wound  so  made  that  its  outer  aspect 
measures  about  5  mm.  and  its  inner  aspect  4  mm.  The  capsule 
is  then  freely  opened  with  a  sharp  hook  or  cystotome.  The  soft 
lens-substance  then  presses  forwaid  into  the  pupil,  and  its  com- 
plete discharge  from  the  eye  is  assisted  by  causing  the  wound  to 


FLAP    EXTRACTION.  371 

gape  by  means  of  a  Daviel  spoon,  while  slight  pressure  is  made 
with  the  finger  on  the  margin  of  the  cornea  opposite  the  spoon. 
After  the  complete  discharge  of  the  lens,  the  eye  is  closed  with  a 
bandage,  and  the  patient  kept  for  a  day  or  two  quiet  in  bed. 
The  after-treatment,  when  the  course  is  normal,  is  simply  the  use 
of  atropine. 

The  indications  for  this  treatment  are  quite  limited.  Discision 
with  a  broad  needle  is  to  be  preferred  in  cataracts  which  are  wholly 
fluid,  such  as  often  occur  in  childhood.  The  small  wound  made 
by  this  method  in  the  cornea  is  sufficient  to  admit  the  escape  of 
the  fluid  lens-substance  without  the  danger  of  prolapse  of  the  iris. 

If  a  shrinkage  has  already  taken  place  in  a  soft  cortical  cata- 
ract of  some  standing,  it  has  no  longer  the  consistence  desirable 
for  the  linear  extraction,  and  generally  discision  is  indicated.  In 
cases  in  which  posterior  synechia  exist,  or  in  which  the  presence 
of  a  hard  nucleus  is  probable,  the  best  method  is  that  by  the 
peripheral  linear  incision,  which  is  yet  to  be  described. 

Until  late  years,  the  method  by  the  flap  incision,  suggested  by 
Daviel  in  1748,  was  the  only  one  practised  for  cataracts  with  a 
hard  nucleus. 

This  method  was  as  follows.  The  cataract  knife  was  inserted 
in  the  cornea  about  1  mm.  from  its  margin,  carried  forward  with 
its  surface  parallel  to  the  iris,  and  the  counter-puncture  made  at 
the  opposite  and  symmetrical  point  of  the  cornea.  The  incision  is 
ended  by  pushing  the  knife  still  farther  toward  the  median  line, 
directing  it  in  such  a  way  that  the  entire  wound  will  be  parallel 
with  the  margin  of  the  cornea. 

The  flap  may  be  made  in  any  convenient  direction,  and  this  is 
generally  downward.  By  reason  of  its  shape,  the  cataract  knife, 
so  long  as  it  is  pushed  forward,  completely  fills  the  corneal  wound, 
and  accordingly  the  aqueous  humor  is  retained  until  nearly  the 
completion  of  the  incision. 

The  escape  of  the  aqueous  humor  is  followed  by  a  correspond- 
ing concentric  diminution  of  the  volume  of  the  entire  eyeball. 
The  lens  and  iris  are  pushed  forward,  and  come  in  apposition  with 
the  posterior  surface  of  the  cornea.  In  many  cases,  however, 
especially  in  old  persons,  the  sclera  is  so  rigid  that  after  the  escape 
of  the  aqueous  humor  it  prevents  the  necessary  compensating 
change  in  the  form  of  the  eyeball.     The  lens  and  iris  cannot  then 


372  FLAP    EXTRACTION. 

come  forward  sufficiently,  and  consequently  the  cornea  sinks  in 
and  becomes  wrinkled.  After  the  removal  of  the  lens,  this  so- 
called  collapse  of  the  cornea  is  still  greater. 

The  second  act  of  the  operation  consists  in  opening  the  capsule 
of  the  lens  by  splitting  it  freely  in  several  directions  with  a 
cystotome  or  cataract  needle. 

The  third  act  is  the  removal  of  the  lens.  Its  normal  position, 
parallel  with  the  base  of  the  cornea,  must  be  changed  so  that,  for 
instance,  with  a  flap  incision  made  downward  the  lower  edge  of 
the  lens  comes  forward  and  presents  in  the  wound.  To  accomplish 
this  it  is  often  sufficient  to  direct  the  patient  to  look  upward.  The 
muscular  contraction  involved  in  this  effort  exercises  a  compression 
of  the  entire  contents  of  the  eyeball,  and  as  this  pressure  meett? 
with  no  resistance  opposite  the  wound,  the  margin  of  the  lens, 
which  lies  just  here,  is  forced  forward.  If  this  physiological 
pressure  prove  insufficient,  it  must  be  supplemented  by  external 
pressure  acting  in  the  same  direction.  To  this  end  slight  pressure 
is  made  upon  the  margin  of  the  cornea  in  the  direction  of  the 
centre  of  the  eyeball,  by  means  of  the  Daviel  spoon,  or,  better 
still,  with  the  margin  of  the  upper  lid  ;  the  edge  of  the  lens 
being  thus  forced  up  into  the  wound,  its  escape  is  assisted  by  a 
slight  pushing  movement.  The  lens  first  pushes  before  it  that 
portion  of  the  iris  lying  behind  the  wound,  and  then  appears  in 
the  pupillary  opening.  As  soon  as  its  greatest  diameter  is  engaged 
in  the  pupil,  the  pressure  must  be  lessened  or  entirely  removed.  If 
necessary,  it  is  better  to  work  directly  upon  the  now  exposed  lens 
with  the  Daviel  spoon,  or  hook  it  with  the  cystotome. 

After  removing  the  lens,  the  iris  is  to  be  replaced  in  its  normal 
position,  and  the  discharge  of  any  remaining  portions  of  cortical 
substance  effected.  If  possible,  both  should  be  accomplished 
simply  by  manipulation  of  the  eyelids.  Soft  circular  rubbing 
movements,  made  by  the  upper  lid  upon  the  cornea,  restore  the 
normal  shape  of  the  cornea,  and  roll  the  remaining  cortical  sub- 
.stance  together  in  the  pupillary  space,  whence  it  can  be  discharged 
through  the  wound  by  gliding  movements  of  the  upper  lid.  As 
the  last  act  of  the  operation,  Von  Hasner*  recommends  a  slight 
puncture  of  the  vitreous  body  in  the  depression  left  by  the  lens. 

*  Klinische  Vortriige,  pag.  305. 


FLAP    EXTRACTION.  373 

A  well-healed  flap  extraction  is  certainly  one  of  the  most  satis- 
factory operative  results.  There  remains  in  the  cornea  a  scarcely 
visible  peripheral  scar,  the  pupil  retains  its  normal  size  and  move- 
ment, only  the  flatness  and  deep  position  of  the  iris  and  its  oscil- 
lation during  movements  of  the  head  betray  the  absence  of  the 
lens.  But  so  satisfactory  a  result  is  by  no  means  certain ;  indeed, 
it  is  attained  in  scarcely  half  the  cases. 

The  healing  is  often  interfered  with  or  delayed  by  some  cause 
or  other,  and  the  result  is  very  imperfect  vision,  or  even  absolute 
blindness. 

It  is  evident  that  the  operation,  even  when  skilfully  performed, 
must  be  regarded  as  a  very  serious  one. 

Xearly  one-half  the  cornea  is  cut  off"  from  its  natural  source  of 
nutrition,  and  it  is  difficult  to  see  how  a  compensating  collateral 
su[)ply  is  possible.  That  this  defective  nutrition  is  frequently  the 
cause  of  necrosis  of  the  coruea  cannot  be  doubted.  The  extensive 
semicircular  wound  never  closes  accurately,  and,  instead  of  healing 
bv  first  intention,  a  suppurative  process  may  occur  which,  by  de- 
struction of  the  cornea  or  by  consecutive  iritis,  may  prove  ruinous. 
The  form  of  the  wound  inclines  it  so  little  to  spontaneous  closure 
that  any  traction  or  pressure  on  the  eye,  or  any  sudden  movement, 
may  cause  it  to  reopen.  The  escaping  aqueous  humor  will  in  that 
case  float  the  iris  forward,  and  its  prolapse,  with  all  its  unfortunate 
consequences,  the  distortion  of  the  wound,  the  inflation  of  the 
prolapsed  part,  severe  irritation,  etc.,  may  be  the  result  of  this 
accident.  It  is  advisable  to  remove  promptly  any  prolapse  of 
the  iris  which  may  occur  after  an  operation. 

Even  when  the  iris  is  not  injured  in  the  least  by  the  instru- 
ments during  the  operation,  it  is  always  forcibly  stretched  and 
pressed  during  the  passage  of  the  cataract  through  the  pupil, 
especially  in  old  persons,  in  whom  frequently  the  tissue  of  the 
iris  has  become  so  rigid  that  only  a  slight  dilatation  of  the  pupil 
can  be  effected  by  the  atropine.  The  injury  thus  caused  to  the 
iris  is  frequently  proved  by  the  pigment  from  the  uveal  layer 
ibund  on  the  lens  after  its  removal.  At  all  events,  this  method 
of  operation  is  very  likely  to  induce  iritis. 

This  being  true,  it  was  natural  that  attempts  should  be  made 
toward  improving  the  method  of  operation.  Supported  by  the 
experience  of  most  observers,  that  cases  in  which  a  portion  of  the 


374  IRIDECTOMY    WITH    EXTRACTION. 

iris  had  been  accidentally  excised,  proved  quite  as  successful  as 
others,  Von  Graefe*  recommended  the  combination  of  iridectomy 
with  the  flap  incision  in  all  cases  in  which  any  difficulty  was 
experienced  in  performing  the  operation  by  the  old  method, — for 
instance,  when  the  flap  incision  or  the  opening  in  the  capsule  has 
not  been  made  large  enough,  or  when  the  corticalis  appears  so 
strojigly  adherent  as  to  prevent  the  lens  from  slipping  out  easily. 
He  recommended  iridectomy  also  in  cases  where  there  is  imperfect 
closure  of  the  wound,  and  consequently  reason  to  expect  prolapse 
of  the  iris;  and  further,  in  cases  where  there  is  a  small  and  rigid 
puj)il,  with  a  hard  cataract,  or  where,  on  account  of  unripeness, 
portions  of  the  cortical  substance  are  left  behind,  or  where,  in 
ripe  cataracts,  the  same  thing  happens  in  consequence  of  excessive 
viscidity  and  adherence  of  the  cortical  substance ;  further,  in  all 
cases  where,  on  account  of  general  marasmus,  a  deep  position  of 
the  eyeball,  due  to  atrophy  of  the  orliital  fat,  limitation  in  the 
movements  of  the  eye,  collapse  of  the  cornea  from  loss  of  elas- 
ticity in  the  sclera,  or  concentric  shrinkage  of  the  corneal  flap, 
there  is  the  probability  that  the  wound  will  heal  badly.  In  some 
cases  Von  Graefe  performed  iridectomy  at  the  same  time,  and  in 
others  some  weeks  before  the  cataract  operation.  With  reference 
to  the  cff*ect  of  the  iridectomy,  Von  Graefef  came  to  the  conclusion 
that  it  could  neither  avert  total  necrosis  of  the  cornea  nor  partial 
suppuration  of  the  wound,  but  simply  that  the  course  of  this  last 
process  is  to  some  extent  favorably  modified  by  it. 

The  danger  of  circumscribed  suppuration,  aside  from  the  possi- 
bility of  its  becoming  diifuse,  lies  not  so  much  in  the  destruction 
of  the  cornea  as  in  iritis,  propagated  from  the  wound.  Pus  ap- 
pears in  the  anterior  chamber,  and  the  iris  is  swelled  by  a  puru- 
lent infiltration.  This  particular  form  of  iritis  seems  much  in- 
clined to  cause  irreparable  loss  of  vision  by  atrophy  of  the  eyeball. 
The  combination  of  the  extraction  with  an  iridectomy  does  not,  it 
is  true,  do  away  with  the  possibility  of  such  a  propagation,  but  it 
surely  acts  to  a  certain  extent  against  it.  The  process  is  not  so 
often  developed  and  is  not  so  severe.  Adhesions  of  the  iris  to 
the  lens  do  not  form  so  rapidly.     Iridectomy,  moreover,  does  not 


*  Arch.  f.  Ophth.,  1856,  B.  ii.  2,  pag.  247-248. 
t  Klin.  Monatsbl.,  1863,  pag.  141. 


PERIPHERAL    LINEAR   INCISION.  375 

preclude  the  occurrence  of  iritis  due  to  violence  done  the  iris 
during  an  operation  or  to  cortical  substance  left  behind. 

At  the  same  time  Von  Graefe's  experiments  took  another  di- 
rection. The  good  results  following  linear  extraction  of  soft  cata- 
ract suggested  the  idea  that  tlie  method  could  be  employed  also 
in  cataracts  having  a  hard  nucleus.  His  first  experiment*  was  to 
make  an  incision  equal  to  one-fourth  the  circumference  of  the 
cornea  with  a  broad  lance  knife,  on  the  temporal  side,  and  exactly 
at  the  corneo-scleral  boundary ;  the  iris  was  then  seized  in  the 
usual  manner  with  the  forceps  and  excised,  and  the  capsule  freely 
opened  with  the  cystotome.  Lastly,  a  spoon  spatula  was  intro- 
duced behind  the  nucleus  and  its  fragments  thus  brought  out 
through  the  wound. 

Xo  good  fortune  attended  this  practice,  and  it  was  in  no  way 
improved  by  the  use  of  Waldau's  spoon. f  But  somewhat  later, 
Critchett  and  BowmanJ  took  it  up  and  introduced  very  important 
modifications.  The  incision  was  made  at  the  upper  part  of  the 
cornea;  a  broader  lance  was  used,  and  the  wound  made  larger, 
so  as  to  occupy  from  one-fourth  to  one-third  the  margin  of  the 
cornea,  and  tiie  extraction  sjioon  used  was  much  smaller. 

The  principal  difference  between  their  two  methods  of  operation 
was  that  Critchett  made  the  puncture  in  the  cornea  about  1  mm. 
from  its  margin,  while  Bowman  made  it  exactly  at  the  corneo- 
scleral boundary. 

Shortly  previous  to  this,  Jacobson§  had  recommended  a  similar 
peripheral  incision,  laying  great  importance  upon  making  the 
flap  as  large  as  possible,  so  that  the  largest  nucleus  with  the  cor- 
ticalis  about  it  could  pass  through  easily.  Jacobson  therefore 
made  his  incision  in  the  limbus  conjunctivae  cornese.  After  the 
lens  was  removed,  a  broad  piece  from  that  portion  of  the  iris  which 
had  been  bruised  by  the  lens  was  excised  as  far  back  as  its  ciliary 
margin. 

The  method  by  the  peripheral  linear  extraction,  which  Von 
Graefe  finally  practised,  followed  upon  Bowman's  and  Critchett's 

*  Arch.  f.  Ophth.,  1859,  B.  v.  1,  pag.  158. 
f  Die  Auslofl'elung  des  Staares,  Berlin,  18G0. 
+  Ophth.  Hosp.  Rep.,  1865,  vol.  iv.  part  4,  pag.  315  and  332. 
§  Ein  neues  und  gefahrloses  Operationsverfahren  zur  Heilung  des  grauen 
Staars,  Berlin,  1863. 


376  PERIPHERAL   LIxN'EAR    INCISION. 

methods.  Proceeding  on  the  principle  that  upon  a  spherical  sur- 
face the  shortest  distance  between  two  points  must  be  upon  the 
line  of  a  o:reat  circle,  Von  Graefe  arrived  at  the  conclusion  that 
it  was  impossible  witii  a  lance  knife  to  make  a  linear  incision 
long  enough,  since  to  do  it  the  point  of  the  knife  must  be  directed 
toward  the  centre  of  the  eye,  in  which  case  the  iris  and  lens  would 
certainly  be  injured.  But  if  the  incision  be  begun  by  puncture 
and  counter-puncture,  there  is  no  difficulty  in  so  completing  the 
incision  which  shall  unite  these  two  points  that  it  shall  form  a  por- 
tion of  a  great  circle.  The  length  of  the  wound  should  equal  the 
horizontal  diameter  of  the  cornea, — about  11  mm., — and  should 
be  made  at  the  upper  corneal  margin  in  order  to  obviate  as  much 
as  possible  the  optical  disadvantages  connected  with  an  iridectomy. 
The  points  for  puncture  and  counter-puncture  are  determined  by 
imagining  a  tangent  to  be  drawn  from  each  extremity  of  the  hori- 
zontal diameter  of  the  cornea,  then  a  line  parallel  with  this  di- 
ameter and  2  mm.  below  the  uj)per  margin  of  the  cornea.  The 
points  where  this  last  line  intersects  the  tangents  are  the  ones  de- 
sired ;  they  lie  about  1  mm.  from  the  margin  of  the  cornea.  If 
now  the  incision  were  made  exactly  in  the  line  of  the  great  circle 
connecting  tliese  points  of  puncture  and  counter-puncture,  a  por- 
tion of  the  external  wound  would  pass  through  tiie  cornea.  But 
to  insure  its  uniformity  the  incision  should  be  made  entirely  out- 
side the  external  corneal  surface ;  and  still,  since  the  inner  surface 
of  the  cornea  is  larger  than  its  outer  surface,  the  inner  wound  will 
be  entirely  in  the  cornea,  its  ends  slightly,  but  its  middle  more 
decidedly,  removed  from  the  scleral  boundary.  Scarcely  more 
than  one-fourth  of  the  whole  wound  is  in  the  scleral  tissue,  the 
rest  being  in  the  peripheral  zone  of  the  cornea. 

Some  difficulty  attends  the  execution  of  the  incision.  If  the 
blade  be  carried  up,  parallel  to  the  plane  of  the  iris,  the  middle 
portion  of  the  incision  will  be  too  far  in  the  periphery,  involving 
the  danger  of  prolapse  of  the  vitreous.  If,  trying  to  avoid  this 
fault,  the  edge  of  the  knife  be  turned  somewhat  forward  when 
the  incision  is  about  half  completed,  an  abrupt  angle  is  made  in 
the  line  of  the  incision,  which  is  very  unfavorable  for  the  exact 
apposition  of  the  edges  of  the  wound. 

It  is  best  from  the  moment  of  the  puncture  to  give  the  blade 
of  the  knife  the  direction  which  it  is  to  follow  till  the  completion 


PERIPHERAL    LINEAR   INCISION.  377 

of  the  incision, — that  is,  the  flat  of  the  blade  not  parallel  with 
the  iris,  but  its  edge  directed  somewhat  forward.  At  the  same 
time  this  inclined  position  of  the  blade  must  not  be  too  great  when" 
the  aqueous  humor  escapes,  which  generally  happens  as  soon  as 
the  counter-puncture  is  made,  for  the  back  of  the  blade,  if  it  be 
held  too  much  inclined,  rubs  across  the  lens  and  may  tear  the 
zonula  and  displace  the  lens  itself.  For  this  same  reason  the 
knife  should  be  as  narrow  as  possible. 

The  point  of  the  knife  should  not  immediately  be  dii-ected 
toward  the  point  of  counter-puncture,  but  in  order  to  make  the 
inner  aspect  of  the  wound  as  large  as  possible  it  should  at  first  be 
directed  somewhat  downward  and  toward  the  centre  of  the  pupil. 
As  soon  as  the  knife-point,  in  making  the  counter-puncture,  has 
passed  through  the  sclera,  the  aqueous  humor  escapes  under  the 
conjunctiva  and  distends  it  for  a  greater  or  less  extent.  No  at- 
tention should  be  paid  to  this,  but  the  incision  should  be  continued 
in  the  direction  chosen,  till  the  sclera  is  entirely  cut  through.  The 
knife  is  then  freely  movable  under  the  loosened  conjunctiva, 
which  now,  in  order  to  avoid  making  the  flap  too  long,  is  to  be 
cut  through  by  directing  the  edge  of  the  knife  forward.  If  the 
conjunctiva  be  very  distensible,  the  point  of  the  knife  may  not 
come  through  it  at  a  point  corresponding  with  the  counter-puncture 
in  the  sclera,  but  somewhat  higher  up  and  later  in  the  progress  of 
the  incision.  If  this  happen,  the  conjunctival  wound  should  be 
enlarged  with  the  scissors,  so  that  the  conjunctival  flap  may  retract 
well  from  the  prolapsed  iris.  Immediately  upon  the  completion 
of  the  corneal  flap  the  iris  generally  prolapses  spontaneously,  and 
must  then  be  excised. 

The  fixation  forceps  are  given  to  the  assistant,  and  with  the 
straight  iris  forceps  the  conjunctival  flap  is  lifted  away  from  the 
prolapsed  iris  and  reflected  upon  the  cornea.  The  iris  is  then 
grasped  with  the  same  forceps  near  the  temporal  angle  of  the 
wound,  and  carefully  cut  away  by  three  or  four  strokes  with  the 
scissors,  gradually  carried  toward  the  median  angle  of  the  w^ound, 
slight  traction  being  meanwhile  made  with  the  forceps.  A  very 
careful  excision  of  the  iris  is  necessary,  for  by  its  prolapse  and 
incarceration  in  the  wound,  healing  is  interfered  with;  and,  fur- 
thermore, the  prolapsed  portion  may  at  a  later  stage  become  a 
permanent  centre  of  irritation,  or,  giving  rise  to  staphyloma,  may 

25 


37 S  PERIPHERAL,    LINEAR   INCISION. 

destroy  the  normal  curvature  of  the  cornea.  After  the  excision 
of  the  iris,  care  should  be  taken  that  its  cut  edges  are  returned 
to  their  proper  position.  If  the  iris  appear  to  be  caught  in  the 
angles  of  the  wound,  the  attempt  may  be  made  to  replace  it  by 
lightly  rubbing  the  cornea  with  the  convex  surface  of  the  cataract 
spoon.  If  only  the  median  angle  of  the  iris  remain  in  the  wound, 
it  may  frequently  be  released  by  a  delicate  pressure  with  the  back 
of  the  cystotome,  when  introducing  that  for  the  purpose  of  open- 
ing the  capsule.  The  opening  of  the  capsule  should  be  by  free 
incisions,  extending  quite  across  the  lens  at  both  sides  of  the  pupil, 
and  the  cystotome  should  be  bent  in  a  suitable  manner.  This  ma- 
noeuvre, however,  must  be  performed  carefully,  to  avoid  displacing 
the  lenSj  either  by  pressure  or  by  traction,  an  accident  which  may 
easily  occur,  especially  with  hard  cataract. 

When  tlie  way  for  the  exit  of  the  lens  is  thus  made  ready,  its 
removal  is  accomplished  in  essentially  the  same  manner  as  in  the 
flap  incision. 

In  the  normal  course  of  the  operation  the  extraction  of  the  lens 
does  not  require  the  introduction  of  a  spoon,  hook,  or  any  other 
instrument.  Just  as  in  the  flap  incision,  the  discharge  of  the  lens 
may  be  effected  by  manipulations  with  the  eyelids.  Since,  however, 
for  making  the  incision  at  the  upper  portion  of  the  cornea,  it  is 
more  convenient,  and  involves  less  danger  of  gaping  of  the  wound, 
to  allow  the  lid  speculum  and  fixation  forceps  to  remain  in  posi- 
tion till  the  escape  of  the  lens,  it  is  best  to  dispense  with  the  use 
of  the  lids,  and  to  use  the  Daviel  spoon,  just  as  many  operators 
do  in  the  flap  operation,  making  with  it  the  necessary  pressure  on 
the  surface  of  the  cornea. 

Von  Graefe  recommended  for  this  purpose  a  spoon-shaped  in- 
strument of  hard  rubber.  A  properly  bent  Daviel  spoon  serves  the 
purpose  very  well.  The  convexity  of  the  spoon  is  laid  upon  the 
lower  margin  of  the  cornea,  and  while  a  constant  pressure  is  exer- 
cised, a  slight  upward  movement  is  made,  causing  the  upper  edge 
of  the  lens  to  appear  in  the  wound,  which  opens  spontaneously. 
Pressure  is  then  made  with  the  spoon,  almost  in  the  direction  of 
the  centre  of  the  eye,  in  order  to  rotate  the  lens  about  its  trans- 
verse axis  and  to  force  it  bodily  into  the  wound.  When  this  is 
accomplished,  the  pressure  is  to  be  gradually  directed  upward,  the 
spoon  thus  forcing  the  lens  before  it,  out  of  the  wound. 


PERIPHERAL    LINEAR    INCISION.  379 

Prolapse  of  the  vitreous  is  the  principal  accident  likely  to  happen 
during  the  operation.  It  may  be  caused  by  the  incision  being  made 
too  far  in  the  periphery,  or  by  luxation  of  the  lens  either  before  or 
during  the  opening  of  the  capsule,  or  by  too  strong  a  pressure  with 
the  s])oon,  especially  when  the  incision  has  been  made  too  small  or 
too  far  in  the  periphery.  Finally,  it  may  be  caused  before  the  escape 
of  the  lens  by  too  strong  a  pressure  on  the  part  of  the  patient,  or 
by  a  pre-existing  looseness  or  partial  atrophy  of  the  zonula,  which 
is  especially  to  be  feared  in  over-ripe,  shrunken  cataracts. 

If  prolapse  of  the  vitreous  occur  after  the  nucleus  and  the 
greater  part  of  the  cortical  substance  have  escaped,  the  speculum 
and  fixation  forceps  should  be  removed,  and  the  attempt  made  by 
manipulating  the  lids  to  expel  the  remaining  fragments  of  the 
cortical  substance.  A  repeated  introduction  of  the  spoon  is  not 
advisable,  and  generally  does  not  accomplish  its  object,  for,  the 
hollow  of  the  spoon  being  filled  with  the  viscid  vitreous  substance, 
no  sufficient  hold  can  be  obtained  upon  the  cortical  fragments.  If 
prolapse  of  the  vitreous  occur  before  the  escape  of  the  lens,  it  may 
nevertheless  often  be  expelled  without  the  introduction  of  an  in- 
strument. If  this  be  found  impossible,  and  if  the  nucleus  be  small 
and  the  corticalis  soft,  it  is  best  to  open  the  capsule  and  extract 
the  nucleus  with  a  broad  but  very  thin  spoon.  Still,  against  the 
extraction  with  the  spoon  there  is  the  objection  that  the  nucleus 
lying  in  the  spoon  is  always  pressed  forward  against  the  uveal 
layer  of  the  iris.  In  the  case  of  large  hard  cataracts,  therefore,  I 
prefer,  by  means  of  a  small,  sharp  hook  inserted  into  its  posterior 
surface,  to  draw  out  the  nucleus,  or  even  the  entire  lens,  without 
previously  opening  the  capsule. 

Hemorrhage  into  the  anterior  chamber  during  the  course  of  the 
operation  is,  to  a  certain  extent,  emban'assing.  This  occurs  most 
frequently  in  eyes  in  which,  on  account  of  the  rigidity  of  the  sclera, 
the  cornea  collapses  under  the  atmospheric  pressure,  immediately 
after  the.  escape  of  the  aqueous  humor;  the  blood  from  the  con- 
junctival wound  may  then  be  said  to  be  forced  "ex  vacuo"  into 
the  anterior  chamber.  If  the  tension  of  the  muscles  be  relieved 
by  deep  chloroform  narcosis,  considerable  difficulty  is,  under  these 
circumstances,  often  experienced  in  expelling  the  blood  from  the 
anterior  chamber.  The  operation  is  thus  made  more  difficult,  but 
its  results  are  not  interfered  with. 


380  PERIPHERAL    LINEAR   INCISION. 

In  the  course  of  healing,  all  those  unfavorable  conditions  may 
occur  which  have  been  mentioned  as  occurring  in  the  flap  opera- 
tion, but  statistics  abundantly  prove  that  they  are  much  less  likely 
to.  Prolapse  of  the  iris  may  be  avoided  by  the  proper  perform- 
ance of  the  operation ;  it  may,  however,  happen  if  the  iris  be  not 
excised  up  to  the  angles  of  the  wound,  or  if  it  remain  caught  in 
them.  Complete  necrosis  of  the  cornea  and  partial  suppuration 
of  the  wound  are  both  of  them  less  frequent  with  this  operation 
than  with  the  flap  incision.  A  mild  iritis,  during  which  a  few 
small  posterior  synechise  form,  but  involving  no  further  optical 
disadvantages,  is  very  frequent.  Severe  forms  of  purulent  iritis 
or  irido-choroiditis,  in  the  normal  coui'se  of  recovery  from  the 
operation,  are  rare. 

Under  ordinary  circumstances  the  after-treatment  is  very  simple. 
After  removal  of  the  coagulated  blood  from  the  conjunctival  sac 
a  bandage  is  applied,  which,  if  necessary,  may  be  renewed  twice 
daily.  Atropine  should  be  used  from  the  first,  in  view  of  the 
tendency  to  iritis.  For  some  days  the  patient  should  lie  quiet, 
though  after  the  third  day  he  may  be  allowed  to  sit  upright  in 
the  bed  for  a  short  time  at  first,  increasing  the  time  gradually 
from  day  to  day.  Generally  he  can  leave  the  bed  at  the  end  of 
the  first  week.  The  period  elapsing  before  complete  recovery 
averages  from  two  to  three  weeks. 

The  operation  may  be  performed  either  with  or  without  chloro- 
form. If  the  first  method  be  chosen,  the  narcosis  must  be  profound 
before  the  operation  is  begun.  But,  even  though  it  be  carried 
so  far  that  the  orbicularis  is  fully  relaxed,  and  the  speculum  and 
fixation  forceps  are  applied  without  causing  the  slightest  spasm 
of  the  lids,  it  is  by  no  means  certain  that  the  operation  can  be 
carried  on  uninterruptedly  to  the  end.  There  are  patients  who, 
during  the  operation,  do  not  awake  from  the  narcosis,  but,  while 
wholly  unconscious,  fall  into  a  sort  of  combined  asphyxia  and 
delirium,  which  interrupts  the  operation  very  annoyingly. 

If  a  subcutaneous  injection  of  morphine  be  given  about  a  quarter 
of  an  hour  before  the  operation,  a  quiet  narcosis  is  more  likely,  but 
not  absolutely  certain,  to  be  had. 

Vomiting  may  very  seriously  disturb  the  course  of  the  opera- 
tion, even  though  for  a  day  previous  the  patient  has  eaten  but 
very  little,  and  for  several  hours  nothing  at  all.     Another  dis- 


PERIPHERAL   LINEAR    INCISION.  381 

advantage  attending  narcosis  is,  that  in  many  cases,  for  the  success 
of  the  operation,  the  complete  relaxation  of  the  ocular  muscles  is 
undesirable. 

With  a  patient  who  possesses  the  necessary  nerve,  it  is  pleasanter 
to  operate  without  chloroform,  and  although  the  behavior  of  the 
patient  cannot  with  certainty  be  foretold,  the  same  uncertainty 
exists  with  reference  to  his  behavior  during  narcosis. 

If  there  be  cataract  in  both  eyes,  both  may  be  operated  on  at 
the  same  time.  It  is  advisable,  however,  to  allow  an  interval 
between  the  two  of  about  four  days.  If  the  course  of  healing 
up  to  that  time  be  normal,  an  unfavorable  change  is  hardly  to  be 
feared. 

If  there  be  cataract  in  but  one  eye,  the  decision  of  the  much- 
mooted  question,  whether  an  operation  is  desirable  or  not,  may 
be  left  to  the  patient.  If  the  usefulness  of  the  second  eye  be 
already  somewhat  impaired  by  incipient  cataract,  the  operation 
upon  the  eye  first  affected  is  always  advisable.  So,  too,  when 
the  eye  not  affected  by  cataract  is  very  near-sighted.  He  can 
use  this  eye  for  near  vision,  reading,  etc.,  and  by  the  operation 
on  the  other  eye  he  obtains  distinct  distant  vision. 

Finally,  mention  must  be  made  of  a  modification  of  the  method 
of  extraction, — that  is,  extraction  of  the  lens  with  the  capsule. 
Where  there  is  pre-existing  relaxation  of  the  zonula,  this  practice 
can  often  _  be  adopted  without  any  difficulty ;  if,  however,  the 
zonula  retain  its  normal  strength,  this  method  must  be  regarded 
as  too  severe,  for  it  cannot  be  carried  out  without  introducing 
into  the  eye  some  powerfully  acting  tractive  instruiiient.  On 
the  whole,  the  general  results  of  the  operation  have  not  been 
encouraging. 

Peripheral  linear  extraction  cannot  be  performed  without  an 
iridectomy,  for,  owing  to  the  peripheral  position  of  the  incision, 
the  iris,  if  it  were  not  excised,  would  prolapse  without  there  being 
any  possibility,  during  the  course  of  healing,  of  replacing  and 
retaining  it  in  its  normal  position. 

In  order  to  avoid  the  excision  of  the  iris  without  resorting  to 
the  flap  incision,  Weber's*  method  may  be  employed.  In  this 
operation  the  incision  is  made  with  a  curved  lance,  10  to  12  mm. 

*  Arch.  f.  Ophth.,  B.  xiii.  1,  pag.  187. 


382  DiscisiON. 

broad,  whose  concave  under  surface  is  curved  on  a  radius  of  10.7 
mm.  The  lance  is  introduced  exactly  in  the  plane  of  the  base  c^ 
the  cornea,  and  is  carried  forward  till  it  almost  touches  the  point 
in  the  corneal  margin  diametrically  opposite  the  place  of  punc- 
ture. This  gives  an  incision  of  sufficient  size.  The  capsule  is 
then  freely  opened,  and  the  expulsion  of  the  lens  accomplished 
by  slight  continuous  pressure  made  on  the  one  side  opposite  the 
wound,  by  the  fixation  forceps  applied  there,  and  on  the  other 
side  by  a  hollow  spatula,  9  or  10  mm.  broad,  whose  margin  is 
laid  along  the  peripheral  lip  of  the  wound.  Of  course  this 
method  may  also  be  combined  with  iridectomy,  in  which  case  it 
is  merely  a  matter  of  choice  whether  this  method  or  the  periph- 
eral linear  incision  be  employed.  For  senile  cataract  I  decidedly 
prefer  the  latter  method,  but  for  the  soft  cataracts  of  young  indi- 
viduals I  prefer  Weber's  method,  without  iridectom}-. 

To  operate  successfully  on  cataract  by  discision,  the  patient 
must  be  young,  and  his  pupil  freely  dilatable  by  atropine.  The 
cornea  is  punctured  with  the  discision  needle  at  a  point  opposite 
the  margin  of  the  dilated  pupil,  and  a  small  crucial  incision  is 
made  in  the  middle  of  the  capsule.  The  lens  imbibes  the  aqueous 
humor;  its  cortical  part  becomes  clouded  and  swollen;  flakes  from 
it  protrude  from  the  wound  in  the  capsule  and  become  slowly  ab- 
sorbed. Gradually  the  swelling  extends  to  the  posterior  corticalis, 
which  presses  forward  the  nucleus,  so  that  finally  it  may  fall  out 
of  the  capsule  into  the  anterior  chamber.  If  the  absorption  of 
the  lens  cease,  as  it  may,  owing  to  closure  of  the  wound  in  the 
capsule,  the  discision  should  be  repeated,  the  opening  being  made 
more  extensive,  till  a  perfectly  clear  central  pupil  is  obtained. 

The  time  necessary  for  this,  during  the  first  year  of  life,  is  from 
one  to  two  months,  in  older  persons,  from  six  to  eight  months. 
During  all  this  time  the  pupil  must  be  kept  widely  distended  by 
atropine;  for  the  danger  attending  discision  does  not  lie  in  the 
slight  wound,  but  in  the  hurtful  effect  which  the  swelling  lens 
may  exercise  upon  the  iris.  The  iritis,  excited  by  the  fragments 
of  the  corticalis,  or  by  the  lens  falling  forward  into  the  anterior 
chamber,  may  assume  a  purulent  character,  and  the  eye  be  de- 
stroyed by  panophthalmitis ;  or  a  membranous  growth  may  de- 
velop from  the  uveal  layer  of  the  iris,  proving  finally  a  complete 
optical  barrier  to  vision,  or  leading  to  atrophy  of  the  eye  from 


DiscisiON.  383 

irido-cyclitis ;  or  a  glaucomatous  increase  of  intraocular  pressure 
may  develop,  which  increases  steadily,  with  corresponding  contrac- 
tion of  the  visual  field,  and  excavation  of  the  optic  nerve,  ending 
in  complete  blindness. 

This  last-named  complication  is  particularly  to  be  feared  in 
cases  where  the  swelling  lens,  pressing  against  the  posterior  surface 
of  the  iris,  forces  it  forward.  If  symptoms  of  iritis  appear  which 
do  not  yield  to  atropine  mydriasis,  or  if  a  severe  inflammation 
develop,  or  if,  without  any  external  signs  of  inflammation,  vision 
become  defective  in  the  periphery  of  the  visual  field,  while  the 
tension  of  the  eyeball  increases,  the  puncture  of  the  anterior 
chamber  should  not  be  delayed.  If,  however,  the  tension  per- 
sist, or  if  after  a  short  time  it  return,  the  I'emoval  of  the  swollen 
lens-substance,  either  with  or  without  iridectomy,  is  indicated. 
Iridectomy,  however,  is  generally  unavoidable. 

The  irritability  of  the  iris  in  the  presence  of  the  swollen  lens- 
substance  is  very  varied,  and  depends  mostly  upon  the  age  of  the 
patient.  Children  bear  the  swelling  even  of  the  entire  lens  very 
well,  but  the  toleration  on  the  part  of  the  iris  decreases  with 
increasing  years.  Moreover,  the  irritability  of  the  iris  in  patients 
of  the  same  age  varies.  The  more  easily  atropine  mydriasis  can 
be  produced  and  maintained,  the  better  does  the  iris  resist  the 
irritation  excited  by  the  swelling  of  the  lens. 

Von  Graefe*  therefore  advised  in  all  cases  in  which  discision  is 
to  be  performed  on  a  patient  above  the  age  of  say  15  years,  or  in 
cases  in  which  the  pupil  does  not  dilate  readily  under  atropine,  to 
do  an  iridectomy  some  three  weeks  before  the  discision.  In  fact, 
in  such  cases  as  these,  choice  will  have  to  be  made  between  this 
procedure  and  the  extraction  by  the  peripheral  linear  incision. 

The  general  rules  and  conditions  under  which  discision  is  to  be 
practised  are,  accordingly,  as  follows  : 

1.  Total  opacity  of  the  lens  in  childhood.  If  the  substance 
of  the  lens  have  at  the  same  time  become  liquefied.  Von  Graefe 
recommends  the  use  of  a  rather  broad  needle  in  order  to  allow 
the  escape  of  the  cataract  fluid  together  with  the  aqueous  humor. 

2.  Discision  is  the  principal  method  for  those  partial  opacities 
of  the  lens  in  childhood  which  require  operation. 

*  Arch.  f.  Ophth.,  B.  v.  1,  pag.  173. 


384  TRAUMATIC   CATARACT. 

3.  The  operation  must  be  resorted  to  with  great  caution  at  a 
period  later  than  the  fifteenth  year.  Later  than  the  twenty-fifth 
to  the  thirtieth  year  the  indications  for  the  operation  are  limited 
to  cases  in  which  the  size  of  the  cataract  is  already  diminished  by 
shrinkage.  Secondary  cataract  furnishes  the  principal  indication 
for  the  performance  of  discision  at  an  advanced  age. 

Traumatic  Cataract.  —  The  immediate  consequence  of 
wounds  by  which  the  capsule  of  the  lens  is  opened,  is  an  ab- 
sorption by  the  lens-substance  of  the  aqueous  humor,  to  whose 
influence  it  is  exposed.  The  lens  swells,  becomes  white,  protrudes 
from  the  wound  in  the  capsule,  and,  according  to  the  size  of  this 
wound,  fills  more  or  less  completely  the  anterior  chamber.  Dur- 
ing this  process  the  entire  lens,  or  the  greater  part  of  it,  may  be 
absorbed.  If  the  wound  in  the  capsule  be  very  small,  the  opacity 
may  extend  only  about  the  immediate  neighborhood  of  the  injury 
and  then  remain  stationary;  especially  is  this  likely  to  happen  in 
old  persons  in  whom  the  lens  has  become  hard. 

The  dangers  attending  traumatic  cataract  depend  upon  a  series 
of  various  circumstances.  Much  depends  upon  the  time  of  life 
and  the  irritability  of  the  iris,  as  already  stated,  in  connection 
with  the  operation  of  discision,  which  indeed  is  nothing  more  than 
a  traumatic  cataract  methodically  produced. 

Traumatic  cataract  is  frequently  only  a  part  of  a  complicated 
injury.  In  many  cases  the  cornea,  sclera,  iris,  or  ciliary  body  is 
also  wounded.  These  complications  may  cause  immediate  loss  of 
vision  by  intraocular  hemorrhage,  detachment  of  the  retina,  or  a 
destructive  irido-cyclitis  or  choroiditis. 

In  recent  and  slightly  complicated  cases,  atropine  is  to  be  used 
to  cause  and  maintain  a  complete  dilatation  of  the  pupil  in  order 
to  withdraw  the  iris  from  irritating  contact  with  the  swollen  lens- 
substance.  If  this  complete  mydriasis  can  be  maintained,  no  other 
treatment  is  necessary  in  the  majority  of  cases,  especially  in  chil- 
dren. If,  however,  the  mydriasis  be  only  partial,  if  iritis  have 
already  appeared,  and  do  not  yield  to  atropine,  or  if  symptoms 
of  glaucoma  appear,  then,  according  to  the  circumstances  of  the 
case,  the  indication  exists  for  either  puncture  of  the  cornea,  iridec- 
tomy, the  linear  extraction  of  the  swollen  lens  either  with  or 
without  iridectomy,  or  the  peripheral  linear  extraction. 

The  worst  cases  of  traumatic  cataract  are  those  which  are  caused 


CAPSULAR    CATARACT.  385 

by  a  foreign  body,  such  as  a  piece  of  percussion-cap,  or  a  splinter 
of  glass  or  stone.  It  is  only  exceptionally  that  the  foreign  body 
remains  imbedded  in  the  lens.  When  a  fragment  of  iron  lodges 
in  the  lens,  its  oxidation  generally  imparts  a  peculiar  rust  color 
to  the  surrounding  lens-substance.  The  arrest  of  the  foreign 
body  in  the  lens  is  always  a  fortunate  circumstance,  for  in  that 
case,  as  a  rule,  the  sad  consequences  attending  the  lodgment  of 
a  foreign  body  in  the  deeper  parts  of  the  eye  are  avoided.  The 
operation  for  cataract  extraction  indicated  under  these  circum- 
stances- must  be  so  performed  that  the  foreign  body  is  removed 
with  the  lens. 

If  a  foreign  body  penetrate  deeply  into  the  eye,  it  is  very 
seldom  that  a  useful  degree  of  vision  is  retained.  As  a  rule, 
blindness  follows  from  detachment  of  the  retina,  chronic  relapsing 
irido-choroiditis,  or  irido-cyclitis.  Frequently,  too,  there  is  danger 
of  sympathetic  affection  of  the  second  eye.  If,  under  these  cir- 
cumstances, the  injured  eye  be  blind,  and  show  sym'ptoms  of  irido- 
cyclitis, its  enucleation  is  the  best  practice  by  which  to  insure  the 
safety  of  the  other  eye. 

By  capsular  cataract  is  understood  an  opacity  of  that  portion  of 
the  lens  immediately  beneath  the  capsule.  Opacities  upon  the 
external  surface  of  the  capsule,  as,  for  instance,  those  left  by  fritis, 
are  therefore  not  designated  as  capsular  cataracts. 

The  conditions  for  the  development  of  capsular  cataract  always 
exist  when  disorganized  and  softened  lens-substance  is  separated 
from  the  aqueous  humor  simply  by  the  anterior  capsule.  The 
fluid  components  of  the  external  cortical  layers  filter  through  the 
capsule,  leaving  behind  on  its  inner  surface  a  precipitate  consist- 
ing of  the  detritus  of  disorganized  lens-substance. 

This  interchange  between  the  aqueous  humor  and  the  lens- 
substance  is  naturally  most  active  in  the  pupillary  region,  and  just 
this  place  is  therefore  most  predisposed  to  the  formation  of  cap- 
sular cataract.  In  simple  senile,  over-ripe  cataract,  the  capsular 
cataract  does  not  generally  extend  far  beyond  the  boundaries  of 
the  pupillary  region.  It  is  characterized  by  its  chalk-white  color, 
its  frequently  somewhat  uneven  surface,  its  irregularly  serrated 
boundary,  and  its  position  in  the  pupillary  region  immediately 
upon  the  inner  surface  of  the  anterior  capsule. 

Upon  microscopic  examination,  the  capsular  cataract  appears  to 


386  CAPSULAR   CATARACT. 

be  an  amorphous,  striated,  or  punctated  mass,  thickest  at  its  centre, 
thinning  toward  its  periphery,  from  which  run  out  irregular  pro- 
jections ;  the  thinner  the  layers  of  this  substance  the  more  trans- 
parent are  they,  and  the  above  named  irregular  thin  projections, 
which  run  out  to  points,  or  interlace  among  one  another,  appear, 
therefore,  frequently  almost  hyaline.  Isolated,  punctated  deposits 
are  frequently  found  on  the  inner  surface  of  the  capsule,  beyond 
the  limits  of  the  principal  opacity. 

At  the  part  where  this  precipitate  adheres  to  the  surface  of  the 
capsule,  the  intra-capsular  cells  generally  break  down,  and  the 
surrounding  cells,  even  in  uncomplicated  cataract,  frequently  show 
slight  signs  of  irritation.  The  capsule  itself  always  remains  trans- 
parent; at  the  place  of  the  deposit  it  is  frequently  somewhat 
thinned,  and  is  always  more  or  less  wrinkled.  This  wrinkling 
of  the  capsule  is  exactly  what  would  be  expected  from  the  nature 
of  the  process  above  described.  If  the  cortical  substance  lose 
its  fluid  constituents  by  filtration  through  the  capsule,  of  course 
there  will  be  a  loss  of  volume,  which  will  be  expressed  by  a 
wrinkling  of  the  capsule. 

Where  capsular  cataract  exists,  the  operation  for  cataract  must 
be  somewhat  modified.  The  capsule  must  be  opened  at  one  side 
of  the  capsular  cataract,  which,  if  possible,  must  be  extracted  with 
the  forceps  or  hook  in  order  to  avoid  leaving  a  thick  secondary 
cataract. 

With  cataract  complicated  by  irido-choroiditis,  capsular  cataract 
is  not  only  very  frequent,  but  generally  covers  a  considerable  sur- 
face, and  attains  an  unusual  thickness. 

The  participation  of  the  intra-capsular  cells  in  the  development 
of  capsular  cataract  is  another  very  important  factor  in  the  process 
above  described.  They  may  take  on  an  active  proliferation,  lose 
their  hexagonal  or  roundish  form,  become  flat,  elongated,  spindle- 
shaped,  or  stellate,  and  detach  themselves  from  their  normal  sup- 
port upon  the  inner  surface  of  the  anterior  capsule.  This  condition 
may  indeed  extend  to  the  posterior  capsule,  penetrating  in  broad 
curved  lines  the  disorganized  substance  precipitated  on  the  sur- 
face of  the  capsule.  As  this  process  goes  on,  these  proliferated 
cells  appear  to  undergo  gradual  atrophy,  though  meanwhile  the 
proliferation  is  taking  place  in  the  more  peripheral  parts.  This 
proliferation  of  the  intra-capsular  cells,  since  it  occurs  only  in 


SECONDARY    CATARACT.  387 

connection  with   irido-choroiditis,  may  well   be   regarded   as   an 
inflammatory  process. 

Finally,  capsular  cataract  is  a  frequent  occurrence  in  all  those 
forms  of  cataract  which  develop  from  the  very  first  in  the  most 
superficial  layers  of  the  lens, — for  instance,  in  cataracta  centralis 
anterior,  cataracta  traumatica,  and  certain  irregular  forms  of  in- 
cipient cataract. 

There  is  no  cataract  operation,  except  the  extraction  with  the 
capsule,  in  which  the  entire  lens  is  removed  from  the  eye.  The 
capsule,  the  intra-capsular  cells,  and  generally  also  some  of  the 
lens-substance  remain  in  the  eye.  These  constitute  the  starting- 
point  for  a  membranous  formation  which  is  designated  as  second- 
ary cataract.  The  lacerated  capsule  rolls  together,  but  does  not, 
however,  withdraw  entirely  from  the  pupillary  region.  Moreover, 
immediately  after  the  operation,  a  proliferation  of  the  intra-cap- 
sular cells  begins ;  they  spread  out  behind  the  iris,  forming,  in 
some  cases,  a  new  hyaline  membrane.  It  is  often  several  months 
before  these  delicate,  membranous,  secondary  cataracts  attain  such 
a  thickness  as  to  cause  disturbance  of  vision. 

If  a  large  quantity  of  the  cortical  substance  remain  after  the 
operation,  or  if  the  course  of  healing  be  disturbed  by  iritis,  the 
growth  of  the  intra-capsular  cells  increases,  and  the  secondary  cata- 
ract, under  these  circumstances,  attains  a  considerable  thickness. 

In  its  thinnest  form  the  secondary  cataract  appears,  upon  focal 
illumination,  like  a  delicate  spider-web  membrane,  stretched  behind 
the  iris.  Focal  illumination  often  reveals  upon  it  bright  opaque 
lines  or  spots,  caused  by  remaining  lens-substance,  by  the  products 
of  iritis,  or  by  folds  in  the  capsule. 

The  disturbance  of  vision  caused  by  secondary  cataract  may  be 
best  determined  by  observing  first  the  degree  of  opacity  by  ex- 
amination with  focal  illumination  and  the  plane  mirror,  and  then 
testing  vision  with  correcting  glasses  and  the  stenopaic  apparatus, 
combined,  perhaps,  with  atropine  mydriasis.  The  improvement 
of  vision  caused  by  the  stenopaic  apparatus  is  in  many  cases  so 
great  that  it  is  sufficient  to  provide  cataract  spectacles,  especially 
such  as  are  intended  for  near  vision,  with  such  a  stenopaic  ar- 
rangement. If  such  a  correction  do  not  prove  sufficient,  an 
operation  is  to  be  resorted  to. 

It  would  seem  most  rational  at  first  sight  to  extract  the  second- 


388  LUXATION    OF    THE    LENS. 

arv  cataract;  for  which  purpose  only  a  very  slight  linear  wound  at 
the  margin  of  the  cornea  is  sufficient.  In  this  way  a  perfectly 
clear  pupillary  region  is  obtained.  But  this  slight  operation  is 
more  dangerous  than  it  appears,  and  may  cause  purulent  choroid- 
itis. Perhaps  this  is  because  the  traction  made  upon  the  cataract 
is  easily  transferred  to  the  ciliary  body,  either  through  the  zonula 
or  by  the  direct  adherence  of  the  cataract.  Discision  is  a  more 
certain  method  ;  but  even  in  this,  the  thicker  portions  of  the  mem- 
brane should  not  be  invaded  unless  necessity  compel  it.  For 
instance,  if  the  natural  ])upillary  region  be  occupied  by  a  thick 
mass,  while  by  the  use  of  atropine  a  thinner  portion  of  the  sec- 
ondary cataract  can  be  uncovered,  it  is  best  to  enlarge  the  pupil 
by  iridectomy  or  iridotomy  so  as  to  include  this  space,  and  there 
perform  discision. 

Frequently  these  thin  membranes  are  so  elastic  and  distensible 
that  it  is  indeed  easy  to  penetrate  them  with  the  discision  needle, 
but  impossible  to  tear  or  cut  them.  For  such  cases,  as  also  for 
very  thick  secondary  cataracts,  Bowman's  operation  with  two 
needles  is  appropriate.  The  needles  are  to  be  inserted  at  two 
points  in  the  periphery  of  the  cornea  diametrically  opposite  each 
other,  and  so  directed  that  their  points  meet  in  the  cataract.  If 
now  the  handles  of  the  needles  be  moved  toward  each  other  their 
points  will  be  separated,  and  by  their  opposite  action  the  cataract 
can  be  freely  torn  without  violence  to  the  zonula. 

Reclination  may  be  appropriate  for  many  cases  of  secondary 
cataract. 

LUXATION    OF    THE    LENS. 

A  dislocation  of  the  lens  from  its  natural  position  necessarily 
involves  a  series  of  changes  which  furnish  the  data  for  a  certain 
diagnosis.  In  the  first  place,  the  lens  itself  shows  an  abnormal 
movement;  its  oscillations  during  movements  of  the  eyeball  are 
distinctly  visible,  and  this  symptom  alone  suffices  to  show  that 
its  normal  attachments  have  become  loosened,  even  though  the 
displacement  be  but  very  slight.  That  part  of  the  iris  from 
which  the  lens  is  removed  loses  its  support,  and  a  tremulousness 
can  be  seen  in  it  with  every  movement  of  the  eye.  Often,  too,  it 
lies  deeper  in  the  anterior  chamber,  at  this  part,  while  on  the 
opposite  side  it  is  pressed  forward  by  the  revolution  of  the  lens  on 
its  transverse  axis.     If  the  dislocation  of  the  lens  be  so  srreat  that 


LUXATION    OF   THE    LENS.  389 

its  margin  appears  opposite  the  pupil,  either  in  its  normal  con- 
dition or  when  dilated  with  atropine,  the  position  of  the  equat#i' 
of  the  lens  can  be  determined  with  the  greatest  exactitude.  Upon 
ophthalmoscopic  illumination  it  appears  as  a  dark  zone,  and  upon 
focal  illumination  as  a  bright  one. 

Luxation  of  the  lens  occurs  congenitally,  and  not  infrequently 
is  inherited.  In  such  cases  the  lens  is  generally  transparent,  but 
abnormally  small,  and  often  so  movable  that  when  the  head  is 
thrown  forward  it  drops  through  the  pupil  into  the  anterior 
chamber,  and  upon  bending  the  head  backward  it  slips  behind 
the  iris  again.  There  is  generally  also  in  these  cases  a  certain 
degree  of  congenital  amblyopia,  so  that  perfect  vision  cannot  be 
obtained  by  correcting  with  lanses  the  aphakia  existing  in  part  of 
the  pupil. 

Traumatic  luxation  of  the  lens  may  be  caused  by  a  contusion 
of  the  eye  or  by  a  violent  jar  of  the  entire  body,  and  may  occur 
either  with  or  without  any  other  injuries. 

It  is  not  improbable  that  in  many  cases  there  is  a  predisposition 
to  traumatic  luxation  of  the  lens,  owing  to  an  abnormal  weakness 
of  its  attachments,  for  occasionally,  acquired  luxation  of  the  lens 
occurs  without  any  apparent  cause.  This  individual  predisposition 
may  explain  the  fact  that  luxation  of  the  lens  from  non-traumatic  as 
well  as  traumatic  causes  frequently  occurs  in  both  eyes.  If  a  part 
of  the  pupil  be  occupied  by  a  luxated  but  transparent  lens,  while 
there  is  aphakia  in  the  remaining  part,  there  may  still  be  monocu- 
lar diplopia,  in  spite  of  the  great  difference  of  refraction  in  the 
two  parts  of  the  pupil,  and  this  generally  disappears  when  the 
aphakia  is  corrected  by  convex  lenses.  The  rays  refracted  in  the 
luxated  lens  then  form  upon  the  retina  large  circles  of  diffusion, 
which  cannot  concur  with  the  distinct  retinal  image  cast  through 
the  free  portion  of  the  pupil. 

If  a  portion  of  the  equator  of  the  lens  fill  the  pupil  completely 
when  contracted,  there  is  generally  considerable  disturbance  of 
vision  from  the  regular  and  irregular  astigmatism,  due  to  the 
inclined  position  of  the  lens  and  the  irregular  refraction  of  light 
through  its  margin.  Vision  is,  of  course,  still  poorer  when  the 
luxated  lens  is  at  the  same  time  clouded.  If,  under  these  circum- 
stances, aphakia  can  be  produced  in  a  portion  of  the  pupil  l)y 
atropine  mydriasis,  it  is  generally  possible  to  obtain  a  considerable 


390  APHAKIA. 

improvement  of  vision  by  the  correcting  convex  glasses,  and  for 
such  cases  the  continued  use  of  atropine  is  advisable. 

Iridectomy  or  iridotomy  is  necessary  in  these  cases,  when,  from 
adhesions  due  to  iritis,  or  from  any  other  cause,  mydriasis  cannot 
be  produced  or  maintained. 

The  luxated  lens  may  remain  a  long  time  transparent,  or  may 
grow  gradually  opaque. 

The  influence  of  the  luxation  upon  the  other  parts  of  the  eye 
varies.  In  one  class  of  cases  no  further  accidents  follow,  while 
in  others  a  glaucomatous  process  comes  on  which  ends  in  blind- 
ness unless  checked  by  iridectomy  or  the  extraction  of  the  luxated 
lens  in  its  capsule. 

The  luxated  lens  may  drop  forward  into  the  anterior  chamber 
and  become  adherent  to  the  cornea.  Iritis  or  irido-choroiditis 
generally  then  develops  either  with  or  without  glaucomatous 
symptoms.  Under  these  circumstances  it  is  sometimes  possible 
to  extract  the  adherent  lens  by  the  linear  incision. 

Cases  in  which  luxation  of  a  calcified  lens  occurs  as  a  conse- 
quence of  irido-choroiditis  have  been  already  referred  to  on  pages 
338  and  369. 

It  sometimes  happens  with  severe  contusions  of  the  eyes  that 
the  sclera  is  torn  through  at  a  point  anterior  to  the  insertion  of  the 
recti  muscles,  generally  upward,  and  the  lens,  escaping  through  the 
opening,  comes  to  lie  beneath  the  conjunctiva.  In  such  cases  it  is 
very  seldom  that  the  uninjured  capsule  still  envelops  the  lens  as 
it  lies  beneath  the  conjunctiva,  but  when  such  is  the  case  the  lens 
may  remain  for  a  long  time  transparent.  As  a  rule,  the  capsule 
is  ruptured,  and  its  fragments,  with  some  of  the  lens-substance 
adhering  to  them,  remain  behind  in  the  eye,  while  the  lens  beneath 
the  conjunctiva  in  a  short  time  becomes  opaque.  In  either  case  a 
simple  incision  of  the  conjunctiva  is  sufficient  for  the  removal  of 
the  lens.  In  spite  of  the  severity  of  this  injury,  many  of  these 
cases  recover  surprisingly  well. 

Aphakia  is  that  condition  of  refraction  which  exists  when  the 
lens  is  absent. 

When  the  lens  is  removed,  the  dioptric  structure  of  the  eye  is 
exceedingly  simple.  In  calculating  its  refraction  there  remain  then 
but  three  factors  :  1,  the  length  of  its  axis,  2,  a  single  refracting 
surface,  the  cornea,  and  3,  the  index  of  refraction,  of  the  intra- 


APHAKIA,  391 

ocular  fluids.  With  an  axis  of  vision  of  normal  leng-th  tlicre 
is  always  a  high  degree  of  hypermetropia  in  connection  with 
aphakia,  so  that  it  is  necessary  to  use  convex  glasses  of  about  4 
inches  focal  length  for  distance,  and  of  about  2|  inches  for  near 
vision.  Of  course,  if  the  axis  of  the  eye  be  abnormally  long 
or  short,  the  convex  glasses  must  be  correspondingly  weaker  or 
stronger. 

In  many  cases  cataract  extraction  produces  both  aphakia  and 
astigmatism.  In  this  acquired  form  of  astigmatism  the  meridian 
of  greatest  curvature  generally  lies  in  the  horizontal  direction, 
exactly  the  opposite  to  the  usual  congenital  meridional  asymme- 
try.* This  statement  has  been  confirmed  by  the  results  of  oph- 
thalmometric  measurements  made  by  Reuss  and  Woinow,t  and  as 
their  observations,  in  a  number  of  cases,  were  made  upon  eyes  both 
before  and  after  the  operation,  they  proved  conclusively  that  the 
astigmatism  was  caused  directly  by  it.  In  twenty-three  cases 
which  were  measured,  both  before  and  after  the  operation,  there 
were  ten  in  which  the  radius  of  curvature  in  the  cornea  had 
become  less  in  the  horizontal  and  greater  in  the  vertical  meridian. 
The  exact  contact  of  the  edges  of  the  wound  is  prevented  by  the 
new  connective  tissue  which  forms  between  them,  and  the  cornea 
consequently  becomes  flattened  in  the  vertical  meridian  in  which 
the  middle  of  the  wound  lies,  while  the  curvature  in  the  hori- 
zontal meridian  is  increased.  Any  abnormity  in  the  healing, 
such,  for  instance,  as  incarceration  of  the  iris,  causes  of  course  a 
higher  degree  and  more  irregularity  of  the  astigmatism.  As  the 
scar  contracts  there  is  a  corresponding  decrease  in  the  astigmatism, 
but  it  never  entirely  disappears.  Under  these  circumstances,  there- 
fore, better  vision  can  be  obtained  by  sphero-cylindrical  than  by 
simple  spherical  lenses. 

Under  physiological  relations  the  processes  to  be  observed  in 
the  lens  certainly  play  the  most  important  part  in  the  function  of 
accommodation,  and  the  conclusion  seems  therefore  unavoidable 
that  aphakia  must  be  accompanied  by  a  total  loss  of  the  power  of 
accommodation.  Still,  assertions  are  constantly  being  met  with 
wdiich  assume  a  power  of  accommodation  in  an  eye  where  there 

*  Haase,  in  Pagenstecher's  klinischen  Beobachtungen,  iii.  pag.  110,  1866. 
t  Ophthalmometrische  Studien,  Wien,  1869. 


392  APHAKIA. 

is  aphakia.*  Coccius  lays  emphasis  upon  the  fact  that  in  many 
persons  the  eyes  move  forward  during  near  vision  and  recede 
somewhat  for  far  vision,  and  since  he  observed  the  same  in  the 
case  where  he  found  accommodation  to  co-exist  with  aphakia,  he 
regarded  it  as  probable  that  the  eye,  by  being  drawn  backward 
by  the  recti  muscles  and  by  pressure  from  behind,  is  made  more 
far-sighted,  and  that  when  drawn  forward  by  the  obliqui  muscles 
and  the  pressure  from  behind  is  relieved,  the  axis  is  slightly 
lengthened,  and  the  eye  is  better  adapted  for  near  vision. 

*  Arlt,  Krankheiten  des  Auges,  B.  ii.  pag.  347;  Coccius,  Der  Mecha- 
nismus  dor  Accommodation,  pag.  55;  Forster,  Accommodationsvermogen 
bei  Aphakic,  Klin.  Monatsbl.  fiir  Augenheilk.,  1872,  pag.  39. 


DISEASES  OF  THE  VITREOUS  BODY. 


Liquefaction  of  the  vitreous  body  occurs  under  normal  re- 
lations as  a  senile  change;  it  occurs  also  frequently  in  myopic 
eyes  with  elongated  visual  axes,  and  also  as  a  consequence  of 
chronic  choroiditis.  The  pathology  underlying  all  these  cases  is 
probably  a  fatty  degeneration  of  the  cells  of  the  vitreous  body. 

If  there  be  at  the  same  time  opacities  of  the  vitreous,  their  great 
mobility  will  give  evidence  of  the  liquefaction  ;  but  if  the  vitreous 
remain  clear,  there  may  be  absolutely  no  symptoms  of  the  condition, 
unless,  perhaps,  the  attachments  of  the  lens  have  become  loosened. 

A  slight  oscillation  of  the  margin  of  the  lens,  occurring  during 
movements  of  the  eye,  often  betrays  this  condition  of  senile  lique- 
faction of  the  vitreous,  and  in  cases  of  cataract  is  a  symptom  to 
be  carefully  looked  for,  as  its  appearance  prognosticates  a  prolapse 
of  the  vitreous  during  the  operation  of  extraction. 

Iwanoff*  has  shown  that  detachment  of  the  vitreous  from  the 
retina  is  a  frequent  occurrence.  In  the  majority  of  cases  it  is 
generally  a  condition  following  injuries,  choroiditis,  etc.  Still,  it 
has  been  observed  to  occur  in  myopic  eyes. 

Accordingly,  either  with  the  symptoms  of  an  acute  inflamma- 
tion or  by  a  process  of  gradual  transudation,  a  fluid  may  accu- 
mulate between  the  vitreous  body  and  the  retina,  by  which  the 
vitreous  is  pressed  forward ;  or  a  shrinkage  of  the  vitreous,  caused 
by  disease  of  that  part  itself,  may  be  the  cause  of  the  detachment. 
In  both  cases  there  is  reason  to  fear  that  the  same  causes  may 
induce  detachment  of  the  retina. 

As  yet  there  is  no  certain  method  by  which  to  make  the  oph- 
thalmoscopic diagnosis  of  this  condition. 

Mouches  volantes,  or  myodesopia,  is  the  name  given  to  the  sub- 

*  Arch.  f.  Opth.,  B.  xv.  2,  pag.  1. 

2^  393 


394  OPACITIES    OF   THE    VITREOUS. 

jective  perception  of  the  elements  of  the  vitreous  body.  They 
may  be  observed  in  any  healthy  eye  by  the  method  of  entoptic 
examination,  by  which  their  shadows  are  made  to  fall  upon  the 
retina.  They  appear  as  isolated  rings,  with  a  bright  centre  and 
a  dark  contour,  or  the  objects  may  be  somewhat  darker,  with 
long  branches  or  outrunners,  or  they  may  seem  like  a  string  of 
bright  beads,  or  like  a  folded  membrane,  and  so  on.  Under 
circumstances  which  cause  hypersemia  in  the  head  or  eyes,  as,  for 
instance,  very  often  in  myopia  (page  44),  these  shadows  upon  the 
retina  often  become  so  distinct  as  to  attract  the  attention  of  the 
patient  and  cause  him  anxiety.  These  fears  may  be  pronounced 
groundless,  provided  vision  is  normal  and  the  ophthalmoscopic 
examination  reveals  no  opacities  in  the  vitreous. 

Opacities  of  the  vitreous  occur  in  very  varied  forms ;  often  as 
a  number  of  small,  sharply  defined  bodies,  frequently  having  sev- 
eral sharp,  radiating  points.  They  are  surrounded  on  all  sides  by 
transparent  vitreous  substance,  and,  on  account  of  their  connec- 
tion with  this  surrounding  substance,  are  immovable,  or  nearly  so. 
These  small  fixed  0})acities  of  the  vitreous  are  frequently  not  easy 
to  be  seen,  as  they  are  distinct  only  when  the  accommodation  is 
exactly  adjusted  on  them. 

Generally  they  are  most  easily  found  by  the  examination  in  the 
inverted  image.  After  observing  the  fundus,  the  convex  glass, 
without  altering  its  centring,  is  to  be  withdrawn  gradually  from 
the  eye,  until  it  casts  the  inverted  image  of  the  iris  and  pupillary 
region.  Every  portion  of  the  vitreous  lying  upon  the  line  of  vision 
of  the  observer  comes  thus  in  a  position  to  cast  its  inverted  image 
at  a  distance  for  which  the  examiner's  eye  can  accommodate. 

These  opacities  are  generally  situated  not  far  from  the  optic 
nerve;  there  are  often  several  of  them  present,  which  may  be 
connected  with  one  another  by  delicate  processes.  They  occur  as 
the  consequences  of  choroiditis  or  retinal  disease,  also  in  myopia 
with  staphyloma  posticum,  and  finally  under  otherwise  normal 
relations,  but,  in  such  cases,  generally  late  in  life. 

The  delicate,  veil-like,  broad,  immovable,  or  slightly  waving 
membranes  which  sometimes  form,  are  likewise  not  always  easy 
to  be  seen.  The  hazy  appearance  of  the  fundus  noticeable  in  such 
cases,  particularly  about  the  optic  disc,  may  suggest  the  erroneous 


OPACITIES    OF    THE    VITREOUS.  395 

idea  of  a  retinal  opacity,  and  it  is  only  by  an  accurate  adjustment 
of  the  accommodation,  generally  also  when  the  pupil  is  dilated,  that 
the  uniformly  clouded  veil,  stretched  through  the  vitreous  body, 
can  be  recognized.  If  such  membranes  lie  immediately  behind 
the  lens,  they  can  generally  best  be  recognized  in  the  upright 
image  by  the  help  of  a  weak  convex  lens,  say  ^,  placed  behind 
the  mirror.  Dust-like  opacities  occur,  often  accompanying  chronic 
choroiditis,  but  more  frequently  with  syphilitic  retinitis,  or  even 
without  any  other  visible  changes,  and  in  such  cases  appear  not 
infrequently  to  stand  in  connection  with  syphilis. 

The  vitreous  o]>acities  most  frequent  and  easiest  to  be  seen  are 
dark,  movable,  thread-like,  flocculent,  or  membranous  bodies, 
which  are  set  in  motion  by  the  movements  of  the  eye.  Their 
great  mobility  is  symptomatic  of  liquefaction  of  the  vitreous. 
Still,  such  bodies  may  be  situated  in  fluid  which  has  accumulated 
between  the  detached  vitreous  body  and  the  retina. 

It  is  certain  that  a  great  part  of  these  opacities  are  due  to 
changes  in  the  cell  elements  of  the  vitreous.  Both  the  nature  of 
these  changes  and  their  occurrence  simultaneously  with  other  in- 
flammatory processes  fully  justify  the  designation  of  the  condition 
as  inflammation  of  the  vitreous,  or  hyalitis.  In  fact,  important 
changes  in  the  cell  elements  of  the  vitreous  are  always  found  upon 
anatomical  examination  of  any  eye  which  has  become  fluid  from 
disease  of  its  internal  membranes,  especially  from  disease  of  the 
choroidal  tract.  Frequently  we  find  great  numbers  of  roundish 
cells  whose  nuclei  are  undergoing  division,  often,  too,  containing 
dark  pigment  granules.  Frequently  these  cells  have  numerous 
delicate  anastomosing  processes,  permeating  the  vitreous  in  the 
form  of  a  reticulated  membrane. 

The  essential  symptom  of  an  inflammation  of  the  vitreous  is, 
therefore,  its  opacity.  Its  transparency  is  diminished  during  an 
acute  choroiditis,  and  also  by  the  presence  of  easily  coagulable 
exudative  fluid.  In  those  cases  of  irido-choroiditis  which  go  on 
to  complete  detachment  of  the  retina  and  atrophy  of  the  eyeball, 
a  dense,  fibrous,  shrunken  mass  is  found  lying  in  the  vitreous 
body  immediately  behind  the  lens.  It  appears  to  be  particularly 
in  such  cases  that  osteoma  develops  in  the  vitreous  body.*     The 

*  Virchow,  Geschwiilste,  B.  ii.  pag.  109. 


396  OPACITIES    OF   THE   VITREOUS. 

cases  described  as  ossification  of  the  lens  may  have  been  confounded 
with  this  process  in  the  vitreous  body. 

But  of  course  all  opacities  in  the  vitreous  body  are  not  of  an 
inflammatory  nature.  This  can  scarcely  be  assumed,  for  instance, 
with  reference  to  those  small,  fixed  specks  which  are  occasionally 
found  in  a  vitreous  otherwise  transparent  and  in  an  eye  otherwise 
normal.  Some  such  small  opacities,  from  a  transparent  vitreous 
which  I  have  been  able  to  subject  to  microscopic  examination, 
consisted  only  of  numerous  fine  pigment  granules,  which  appeared 
to  be  contained  in  ramifying  canals. 

Very  dense  vitreous  opacities  sometimes  occur  so  suddenly  that 
they  must  in  all  probability  be  regarded  as  of  hemorrhagic  origin. 

The  disturbances  of  vision  are  caused  by  the  shadows  which 
the  opacities  cast  upon  the  retina.  Small  fixed  opacities  may 
therefore  occur  in  an  otherwise  transparent  vitreous  and  while 
vision  is  unimpaired.  They  appear  to  the  patient  as  dark  specks, 
which  do  not  greatly  change  their  position  in  the  visual  field. 
Delicate  clouded  membranes  or  diffuse  opacities  obscure  vision 
more  or  less,  while  the  large  movable  flakes  cause  a  diffiise  cloud- 
iness, and  in  addition  cast  upon  the  retina  movable  shadows, 
perceptible  to  the  patient. 

Diseases  of  the  choroid  and  retina  are  generally  the  causes  of 
vitreous  opacities.  This  is  perhaps  the  reason  why  it  is  custom- 
ary to  speak  of  choroiditis  as  soon  as  any  vitreous  opacity  appears, 
even  though  no  choroidal  changes  can  be  detected  by  the  ophthal- 
moscope ;  or  cyclitis  is  assumed  when  the  opacity  lies  in  the  ante- 
rior portion  of  the  vitreous.  As  opposed  to  this  view,  it  may  be 
remarked  that  no  reason  can  be  given  why  the  cellular  elements 
of  the  vitreous  may  not  become  independently  diseased  as  well  as 
those  of  the  cornea. 

The  prognosis  is  generally  unfavorable.  In  some  cases  of 
inflammatory  or  hemorrhagic  origin,  it  is  true,  the  opacities  may 
entirely  disappear,  but  as  a  rule  they  are  permanent. 

The  fact  has  been  observed,  especially  in  myopic  eyes,  that 
disease  of  the  vitreous  may  be  the  precursor  of  retinal  disease. 

In  the  treatment  it  is  first  to  be  ascertained  whether  the  exist- 
ence of  syphilis,  hemorrhagic  diseases,  etc.,  indicate  the  pro}7i'iety 
of  any  special  therapeutics. 

In    most   cases    the  indications  exist  for  the  usual  derivative 


RELAPSING    HEMORRHAGES    IN   THE    VITREOUS.  397 

therapeutic  means  employed  for  intraocular  diseases  in  general, 
such  as  bleeding  by  the  artificial  leech,  foot-baths,  cathartics, 
diaphoretics,  mercurials,  or  iodide  of  potassium. 

The  case  reported  by  Von  Graefe,  in  which  complete  restora- 
tion of  vision  was  obtained  by  discision  of  a  membrane  stretched 
transversely  across  through  the  vitreous,  appears  as  yet  to  be  the 
only  such  on  record.* 

Cholesterin  crystals  are  frequently  observed  in  the  vitreous 
body.  They  occur  sometimes  in  connection  with  other  opacities 
of  the  vitreous,  or  as  the  residuum  of  such  opacities,  sometimes  in 
a  vitreous  otherwise  clear,  presenting  no  other  changes  and  where 
vision  is  nearly  perfect.  Ophthalmoscopically  they  appear  as  fine, 
glittering,  trembling  points,  much  brighter  when  illuminated  by 
the  concave  mirror  than  when  the  plane  mirror  is  used.  In  the 
anterior  part  of  the  vitreous  they  can  be  well  seen  by  focal  illu- 
mination. In  the  course  of  some  months  they  may  disappear 
spontaneously. 

Recurring  hemorrhages  into  the  vitreous  are  rare,  but  the  con- 
dition generally  resists  treatment  obstinately,  and  is  a  very  serious 
one. 

Immediately  after  a  hemorrhage  vision  is  generally  much  di- 
minished. In  the  course  of  one  or  two  months  the  effusion  is 
resorbed,  but  only  to  be  followed  soon  by  a  repetition  of  the  pro- 
cess. Small  hemorrhages  do  not  necessarily  cause  disintegration 
of  the  vitreous  tissue,  but  may  simply  indent  the  retinal  surface 
of  the  vitreous,  and  in  such  cases  are  often  enclosed  by  layers  of 
clouded  vitreous  substance.  Frequently  there  exist  simultaneously 
hemorrhages  in  the  equatorial  part  of  the  retina,  and  these  may 
with  greater  probability  be  regarded  as  the  source  of  the  vitreous 
hemorrhages  than  can  those  choroidal  hemorrhages  to  which  Von 
Graefef  ascribed  them.  These  last,  if  they  should  break  through 
the  hyaloid  membrane  of  the  choroid,  would  be  much  more  likely 
to  detach  the  retina  than  to  penetrate  it  through  a  small,  sharply 
defined  opening. 

Nothing  is  known  respecting  the  causes  of  recurring  vitreous 

*  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  102.  f  Ibid.,  B.  i.  1,  pag.  358. 


398  VASCULARIZATION    OF    THE    VITREOUS. 

hemorrhages.  It  is  noticeable  that  they  occur  principally  in 
persons  between  twenty  and  forty  years  of  age. 

The  development  of  blood-vessels  in  the  vitreous  of  eyes  which 
are  already  blind,  in  consequence  of  choroiditis,  is  no  great  rarity. 
The  new  vessels  appear  to  spring  mostly  from  the  retina.  But 
since  in  these  cases  both  the  vitreous  and  the  lens  are  generally 
opaque,  there  is  very  seldom  an  opportunity  for  recognizing  these 
new  vessels  upon  clinical  examination.  If,  however,  the  refracting 
media  before  the  vitreous  remain  transparent,  and  if  the  vessels 
ramify  in  the  hollow  formed  by  the  lens,  they  may  be  easily  seen 
with  the  naked  eye. 

Those  cases  in  which  the  develojjment  of  vessels  must  probably 
be  regarded  as  a  consequence  of  a  retinitis,  as  evinced  by  an  opacity 
and  excessive  hypersemia  of  the  retina,  are  of  an  entirely  diiferent 
nature.  There  are  on  record*  but  two  observations  of  this  kind. 
In  both  the  vitreous  was  clouded,  but  still  sufficiently  transparent 
to  admit  of  the  examination  of  the  fundus.  The  vessels  sprang 
from  the  optic  disc  itself,  or  from  its  neighborhood,  and  s})read 
through  the  posterior  part  of  the  eye,  the  longest  branches  reach- 
ing its  centre. 

In  one  case  one  of  these  branches  was  the  source  of  a  hemor- 
rhage. The  vitreous  opacity  and  the  affection  of  the  retina  Avere 
bilateral,  but  the  development  of  vessels  was,  in  one  case,  confined 
to  one  eye.  In  both  cases,  at  the  height  of  the  disease,  vision 
improved  greatly  as  the  vitreous  cleared  up. 

As  a  very  rare  cause  of  vascularization  of  the  vitreous,  it  should 
be  mentioned  that  in  one  case  of  choroidal  abscess,  probably  a 
suppurated  tubercle  which  penetrated  the  vitreous  body,  Beckerf 
saw  the  development  of  vessels  in  the  vitreous.  A  subsequent 
anatomical  examination  showed  that  they  were  connected  with 
the  retinal  vessels.  The  same  observer  reports  a  case  in  which 
a  vascularized  morbid  growth  developed  in  the  vitreous.| 

In  the  foetus  the  hyaloid  artery  runs  through  the  hyaloid  canal 
from  the  optic  disc  to  the  posterior  pole  of  the  lens.     Stilling§  has 

*  Coccius,  Ueber  Glaucom,   Entziinduiig,  etc.,  Leipzig,  1859,  pag.  47;  E. 
von  Jaeger,  Ophtlialm.  Handatlas,  pag.  117,  Taf.  xv..  Fig.  72. 
f  Berioht  tier  Wiener  Augenklinik,  1867,  pag.  114. 
+  L.  c.,  pag.  106.  I  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  299. 


CYSTICERCUS    IN    THE    EYE.  399 

recently  re-demonstrated  that  the  hyaloid  canal  persists  during 
life,  and  it  appears  that  in  rare  cases,  in  consequence  of  a  slight 
opacity  or  vascularization  of  its  Avails,  it  may  remain  visible  by 
the  ophthalmoscope.*  Somewhat  more  frequently  a  thread  is 
observed  connecting  the  optic  nerve  with  the  posterior  pole. 
This  must  be  regarded  as  the  atrophied  remnant  of  the  hyaloid 
artery. 

Cysticercus  within  the  eye  was  first  observed  in  the  anterior 
chamber.  Ophthalmoscopic  examination  has  shown  that  it  is 
relatively  more  frequent  in  the  deeper  parts  of  the  eye. 

The  cysticercus  appears  as  a  semi-transparent,  bluish-white, 
distinctly  defined  cyst,  upon  which  it  is  often  possible  to  see  the 
movements  of  the  outstretched  neck  and  head,  with  its  sucking 
apparatus.  When  the  ophthalmoscopic  image  is  as  distinct  as  this, 
there  is  no  danger  of  an  error  in  diagnosis.  Frequently,  however, 
the  head  and  neck  are  drawn  in,  and  the  place  upon  the  cyst 
occupied  by  the  neck  appears  simply  as  a  brighter  spot.  If,  under 
these  circumstances,  the  examiner  fix  his  gaze  for,  say  a  minute, 
on  one  particular  point  of  the  cyst,  he  may  frequently  detect  its 
movements.  Still,  in  most  cases  I  have  not  been  able  to  deter- 
mine whether  the  movements  observed  were  spontaneous  on  the 
part  of  the  cyst  or  were  slight  movements  of  the  eye  itself. 

In  the  majority  of  cases  the  cysticercus  lies  originally  between 
the  retina  and  the  choroid,  and  therefore  causes  extensive  detach- 
ment of  the  retina.  At  a  later  period  the  cysticercus  may  l)reak 
through  the  retina  and  penetrate  the  vitreous,  or  it  may  remain 
lying  between  the  retina  and  the  vitreous. 

When  first  observed,  the  cysticercus  is  in  the  vitreous  body  in 
only  about  half  the  cases. 

As  might  be  expected,  aside  from  the  cysticercus,  there  almost 
always  exist  important  pathological  changes.  Opacities  of  the 
vitreous  sometimes  precede  the  appearance  of  the  cysticercus  or 
appear  at  a  later  stage.  The  mechanical  irritation  caused  by  the 
presence  of  the  entozoon  frequently  induces  inflammatory  changes 
in  the  retina  or  choroid.  In  consequence  of  this,  both  membranes, 
and  often,  too,  a  portion  of  the  neighboring  vitreous,  may  grow 

*  Saemisch,  Klin.  Monatsbl.,  1869,  pag.  304. 


400  CYSTICERCUS    IN    THE    EYE. 

together,  forming  a  compact  mass.  Under  these  circumstances 
there  is  frequently  seen  simultaneously  with  the  cysticercus  a 
dirty-white,  strongly  reflecting,  circumscribed  place  in  the  interior 
of  the  eye,  which  does  not,  however,  for  the  moment  necessarily 
correspond  with  the  position  of  the  cysticercus,  which  can  change 
its  place  by  its  own  spontaneous  movements. 

These  changes,  in  the  course  of  time,  make  the  ophthalmoscopic 
examination  impossible.  The  vitreous  and  frequently  the  lens 
become  opaque ;  iritis  and  choroiditis  appear,  and  complete  blind- 
ness, with  atrophy  of  the  eye,  is  the  most  frequent  termination. 

It  is  noticed  that  cysticercus  is  found  in  those  regions  where 
the  taenia  solium  most  prevails,  while  in  those  regions  infested  by 
the  taenia  mediocanellata,  cysticercus  is  almost  never  found  in  the 
eye. 

The  extraction  of  the  cysticercus  from  the  anterior  chamber  is 
generally  not  difficult.  If  it  be  situated  deep  in  the  eye,  it  may 
still  be  possible  to  remove  it  by  means  of  the  peripheral  linear 
incision,  having  first  removed  the  lens.  But  it  is  seldom  that 
vision  can  be  saved.  The  form  of  the  eye  is,  however,  often 
preserved  by  this  operation. 


PART   THIRD. 

NORMAL  FUNDUS ;  DISEASES  OF  THE  CHOROID,  OF  THE 
RETINA,  AND  OF  THE  OPTIC  NERVE;  GLAUCOMA  AND 
AMBLYOPIA. 


401 


OPHTHALMOSCOPIC   IMAGE  OF  THE  iNORMAL  FUNDUS 
OF  THE  EYE. 


The  normal  optic  nerve  is  distinguished  from  the  surrounding 
fundus  by  a  brighter  color,  which  by  daylight  appears  as  a  bright 
yellowish-red.  By  artificial  light  the  yellow  tinge  is  lost,  while 
the  red  still  remains.  The  optic  nerve  therefore  appears  white, 
tinged  with  red.  This  red  tinge  is  caused  by  the  numerous  capil- 
lary blood-vessels  at  the  intraocular  extremity  of  the  optic  nerve. 

The  optic  nerve  is  generally  bounded  by  a  white  line  varying 
in  breadth,  generally  most  distinct  upon  the  temporal  side,  and 
often  surrounding  the  optic  nerve  like  a  ring.  The  anatomical 
cause  for  this  appearance  is  that  between  the  inner  nerve-sheath 
and  the  margin  of  the  foramen  choroidese  a  stripe  of  scleral 
tissue  shines  through  the  retina.  The  breadth  of  this  scleral 
stripe  varies  greatly  in  diiferent  individuals.  Generally  it  is  just 
recognizable  ;  when  it  equals  the  breadth  of  a  retinal  vessel  it  is 
relatively  broad.  As  these  scleral  stripes  increase  in  width  they 
gradually  begin  to  present  the  same  ophthalmoscopic  image  as  do 
the  white  crescents  surrounding  the  optic  nerve  in  myopia  (comp. 
p.  38).      . 

The  margin  of  the  foramen  choroidese  often  forms  a  dark  pig- 
mented ring  surrounding  the  optic  nerve.  Often,  however,  this 
ring  remains  incomplete,  and  at  times  is  only  indicated  by  small 
specks  of  pigment,  generally  most  numerous  on  the  temporal  side 
of  the  optic  nerve. 

The  optic  disc  usually  presents  at  its  centre  a  slight  depression, 
which  sometimes  attains  a  considerable  size. 

The  bundles  of  nerve  fibres  contained  in  the  trunk  of  the  optic 
nerve,  having  arrived  at  its  intraocular  end,  must  necessarily  bend 
in  order  to  pass  into  the  nerve-fibre  layer  of  the  retina.  This 
causes  a  slight  funnel-shaped  depression,  which  is  always  close  to 

the  central  vascular  canal,  and  on  the  temporal  side  of  it.     This 

403 


404  LAMINA    CRIBROSA. 

depression  appears  ophthalnioscopically  as  a  brighter  spot,  varying 
in  size  in  different  individuals,  but  nearly  always  large  enough 
to  admit  the  recognition  of  the  characteristic  appearances  of  the 
lamina  cribrosa  at  its  bottom.  When  sufficiently  magnified,  and 
that  best  in  the  upright  image,  or  in  the  inverted  image  with  con- 
vex 3  or  3^,  the  net-work  of  interwoven  connective  tissue  can  be 
recognized  by  its  brilliant  white  color,  while  the  bundles  of  nerve 
fibres  filling  its  meshes  appear  as  bright-gray  dots.  These  dots 
are  round  when  the  bundles  turn  at  right  angles,  and  are  oval 
when  the  bundles  pass  into  the  retina  in  a  more  oblique  direction. 

With  reference  to  the  ophthalmoscopic  image  of  the  lamina 
criijrosa,  it  is  to  be  remembered  that  every  cross-section  of  the 
optic  nerve,  and  not  simply  the  natural  one  at  its  intraocular 
extremity,  presents  the  appearance  of  a  cribriform  disc.  Ac- 
cordingly, at  whatever  depth  we  are  able  ophthalnioscopically  to 
penetrate  the  optic  nerve,  everywhere  will  we  find  the  image  of 
the  lamina  cribrosa  repeated. 

Anatomically,  however, — and  this  is  the  jioint  to  be  here  par- 
ticularly observed, — only  that  part  of  the  optic  nerve  in  which  the 
tissue  is  intimately  interwoven  with  that  of  the  sclera  is  designated 
as  tlie  lamina  cribrosa.  Fibres  of  the  scleral  tissue  pass  trans- 
versely through  the  optic  nerve,  and  shreds  of  connective  tissue 
bend  out  of  the  optic  nerve  into  the  sclera.  Anteriorly,  this 
place  is  bounded  by  a  slightly  concave  line  in  the  plane  of  the 
choroid  ;  posteriorly,  it  extends  as  far  as  the  middle  of  the  thick- 
ness of  the  sclera.  In  longitudinal  section,  this  portion  is  ex- 
ceedingly distinct,  for  the  reason  that  at  its  posterior  limit  the 
optic-nerve  fibres  lose  their  myelin  sheaths,  in  order,  as  fine 
pale  fasciculi,  to  pass  through  the  connective-tissue  meshes  of  the 
lamina  cribrosa. 

Differences  of  level  at  the  intraocular  extremity  of  the  optic 
nerve  may  be  caused,  as  H.  Miiller*  has  shown,  by  the  behavior 
of  the  external  layers  of  the  retina,  that  is,  of  all  those  layers 
which  lie  external  to  the  nerve  fibres.  If  they  extend  close  up 
to  the  optic  nerve,  the  nerve  fibres  must  ascend  vertically  along 
the  external  layers,  and  then  curve  suddenly.  This  narrows  the 
central  depression.     If,  on  the  contrary,  the  external  layers,  be- 

*Arch.  f.  Ophth.,  B.  iv.  2. 


OPTIC  DISC.  405 

ginning  at  the  optic  nerve,  increase  in  thickness  only  gradually, 
the  curves  made  by  the  nerve  fibres  are  less  abrupt,  the  central 
depression  is  broader  and  deeper,  so  that  the  lamina  cribrosa  is 
seen  at  its  bottom.  This  slight  depression,  as  already  mentioned, 
is  always  on  the  temporal  side  of  the  vessels  of  the  nerve,  and 
therefore  is  nearer  to  the  temporal  than  to  the  median  side  of  the 
optic  nerve. 

H.  Miiller  pointed  out  the  fact  that  very  often  the  mass  of 
nerve  fibres  which  passes  over  the  margin  of  the  place  of  entrance 
of  tlie  optic  nerve  is  not  ecpial  at  all  parts,  but  is  less  upon  the 
side  toward  the  yellow  spot  than  in  the  other  portions.  These 
differences  of  level  are  distinctly  shown  in  the  longitudinal  section 
of  an  optic  nerve  represented  in  Fig.  43. 


Fig.  43. 


1)1 


Vc. 

The  thickness  of  the  intraocular  portion  of  the  optic  nerve  is 
greater  on  the  median  side  at  m  than  on  the  temporal  side  at  t. 
The  trunks  of  the  retinal  vessels  ascend  along  the  median  side, 
but  leave  the  plane  of  the  section  before  they  reach  the  surface 
of  the  retina. 

This  distribution  of  the  optic  nerve  fibres  is  probably  to  be 
explained  by  an  anatomical  peculiarity  of  the  macula  lutea.  The 
fibrous  nerve  layer  is  at  that  place  considerably  thinner  than  at 
any  other  point  equally  distant  from  the  optic  nerve,  because  at 
that  place  are  found  only  those  fibres  whose  extremities  belong  to 
the  macida  lutea  itself,  while  those  fibres  destined  for  the  periphery 
of  the  retina  avoid  this  spot  by  curving  around  it.  It  is  very 
likely  that  in  some  cases  those  nerve  fibres  destined  for  the  tem- 
poral half  of  the  retina  are  arranged,  even  in  the  optic  nerve  itself, 


406  PHYSIOLOGICAL   EXCAVATIOX. 

with  reference  to  this  peculiar  distribution  about  the  region  of  the 
macula  lutea. 

The  temporal  margin  of  the  optic  nerve  is  there  principally 
crossed  by  those  nerve  fibres  which  end  in  the  macula  lutea,  while 
the  remaining  fibres  are  crowded  together  upon  the  median,  upper, 
and  lower  parts  of  the  optic  nerve. 

The  nerve  fibres  which  belong  to  the  temporal  periphery  of  the 
retina,  and  which  serve  for  eccentric  vision  in  the  median  portion 
of  the  visual  field,  will  then  be  found  at  the  upper  and  lower 
portions  of  the  optic  nerve. 

The  above  described  difference  of  level  in  the  optic  nerve  is 
called  a  physiological  excavation  when  the  floor  of  the  central 
depression  lies  below  the  plane  of  the  choroid. 

Upon  anatomical  examination  the  anterior  limit  of  the  lamina 
cribrosa  is  generally  found  on  the  level  of  the  choroid,  but  where 
there  is  physiological  excavation  the  ophthalmoscope  shows  us  the 
characteristic  picture  of  the  lamina  cribrosa  at  a  much  deeper  level, 
for  every  cross-section  of  the  optic  nerve,  at  whatever  distance 
from  the  retina,  shows  this  same  picture.  A  physiological  exca- 
vation more  than  half  a  millimetre  deeper  than  the  plane  of  the 
choroid  is  no  great  rarity. 

The  ophthalmoscopic  picture  of  the  physiological  optic-nerve 
excavation  is  as  follows  : 

One  sees  upon  the  optic  disc  a  bright  spot,  in  which  can  be 
recognized  the  central  vessels  and  the  characteristic  signs  of  the 
lamina  cribrosa,  and  upon  whose  bright  background  the  delicate 
vessels  running  toward  the  macula  lutea  are  sharply  defined. 

At  the  median,  upper,  and  lower  portions  of  the  optic  disc,  the 
bright  spot  is  more  or  less  shar})ly  bounded  by  the  gray-red  mass 
of  the  optic  nerve.  The  greater  part  of  the  nerve  fibres  are  crowded 
together  in  the  form  of  a  crescent,  whose  convexity  is  turned 
toward  the  median  side,  while  its  two  horns,  above  and  below,  are 
directed  toward  the  macula  lutea.  The  nerve  fibres  forming  this 
crescentic  mass  are  seen  ascending  steeply  from  the  floor  of  the 
lamina  cribrosa  and  curving  sharply  into  the  plane  of  the  retina. 

The  vascular  trunks  follow  the  same  course  as  the  nerve  fibres 
surrounding  them.  They  always  ascend  upon  the  median  wall  of 
the  nerve-fibre  layer,  simjdy  because  at  the  intraocular  extremity 


DIAGNOSIS    OF    EXCAVATIONS,  ETC.  407 

of  the  optic  nerve  they  retain  the  same  relative  position  that  they 
do  in  its  orbital  part,  and  because  their  princi})al  branches  for  the 
most  part  run  to  the  median  half  of  the  retina. 

If  one  follow  the  retinal  vessels  from  the  periphery  to  the  optic 
nerve,  they  are  seen  at  the  margin  of  the  excavation  to  bend  over 
hook-shaped.  That  part  of  the  vessel  which  descends  upon  the 
median  wall  of  the  excavation  is  foreshortened  in  perspective,  or 
else  is  not  visible  down  to  the  point  where  it  sinks  into  the  lamina 
cribrosa. 

The  descent  into  the  ])hysiological  excavation  is  often  quite 
gradual ;  in  other  cases  the  margin,  especially  in  its  median,  upper, 
and  lower  portions,  is  very  sharp,  often  indeed  overhanging,  and 
the  walls  steep.  But  it  is  of  great  diagnostic  importance  to 
observe  that  the  margin  of  the  physiological  excavation  never 
coincides  with  that  of  the  optic  disc  itself.  At  the  median  side 
this  is  easily  seen  by  reason  of  the  breadth  and  distinctness  of 
the  nerve-fibre  layer;  but  this  is  more  difficult  upon  the  side 
toward  the  macula  lutea,  because  here  there  is  often  really  no 
sharply  defined  margin  of  the  excavation.  Upon  this  side  the 
slope  .of  the  wall  is  quite  gradual ;  the  surface  of  the  optic  nerve 
rises  gradually  to  the  level  of.  the  retina,  but  always  reaches  it 
before  passing  the  margin  of  the  optic  disc. 

The  diagnosis  of  physiological  excavation  is  made  by  the  help 
of  those  ophthalmoscopical  experiments  by  which  both  in  the 
inverted  and  in  the  upright  image  we  are  enabled  to  detect  dif- 
ferences of  level  in  the  fundus  of  the  eye. 

In  the  examination  in  the  upright  image  the  diagnosis  depends 
u])on  those  laws  which  have  been  given  on  page  96.  If,  for 
instance,  the  eye  be  emmetropic,  so  that  the  plane  of  the  retina 
can  be  distinctly  seen  in  the  upright  image,  without  a  correcting 
lens,  then,  in  order  to  see  distinctly  the  bottom  of  an  excavation, 
a  concave  lens  is  necessary  whose  focal  distance  must  be  so  much 
the  shorter  the  deeper  the  excavation. 

Assuming  complete  relaxation  of  accommodation  for  both  the 
examined  and  the  examining  eye,  a  different  correcting  lens  is 
necessary  for  seeing  the  plane  of  the  retina  than  for  seeing  the 
floor  of  the  excavation,  and  the  depth  of  the  excavation  may  be 
calculated  from  the  difference  between  these  two  glasses.  This 
calculation  may  be  made  by  the  method  which  we  have  employed 


408 


DIAGNOSIS   OF   EXCAVATION. 


on  page  104,  but  in  view  of  all  the  unavoidable  sources  of  error 
the  practical  application  of  this  method  is  quite  limited. 

In  the  examination  in  the  inverted  image  the  greatest  reliance 
is  placed  upon  the  change  in  the  parallax  of  the  ophthalmoscopic 
image,  caused  by  movements  of  the  convex  lens.  The  optical 
principle  involved  is  explained  by  Fig,  44. 

Fig.  U. 


Suppose  the  points  a  and  b  to  lie  upon  the  line  of  vision  of 
the  observer,  c  to  be  the  optical  centre  of  the  convex  lens,  and 
the  points  a  and  b  to  lie  beyond  its  principal  focus,  then  will 
a'  and  b'  represent  the  real,  inverted  images  of  these  points.  If 
now,  without  changing  the  direction  of  the  line  of  vision,  we 
move  the  convex  lens  so  that  its  optical  centre  comes  to  c',  then 
will  the  image  of  the  point  a  be  formed  upon  the  line  ac',  for 
instance,  at  a",  and  the  image  of  the  point  6  upon  the  line  be'  at  b". 

The  image  of  the  point  b  has  moved  farther  from  our  line  of 
vision  than  has  that  of  the  point  a.  Accordingly  the  movement 
of  the  convex  lens  displaces  the  image  of  a  more  distant  jjoint  less 
than  it  does  that  of  a  nearer  one. 

If  now,  during  the  examination  in  the  inverted  image,  slight 
movements  of  the  convex  lens  be  made,  the  entire  sharp  margin 
of  the  physiological  excavation  will  be  seen  to  move  over  the 
lamina  cribrosa.  It  is  still  better  when  the  examiner  fixes  his 
attention  upon  that  portion  of  a  retinal  vessel  which  bends  over 
the  margin  of  the  excavation,  and  then  makes  movements  of  the 
convex  lens  at  right  angles  to  the  course  of  the  vessel.  The  part 
of  the  vessel  fixed,  appears  then  to  move  more  at  the  margin  of 
the  excavation  than  does  that  part  lying  upon  the  lamina  cribrdsa. 


EETIXAL    VESSELS,       VENOUS    PULSATION.  409 

The  starting-point  of  the  central  vessels  generally  lies  slightly 
to  the  inner  side  of  the  centre  of  the  optic  disc.  The  principal 
branches  of  the  retinal  vessels  run  mostly  upward  and  down- 
ward;  only  two  delicate  vessels  start  out  in  the  direction  of  the 
macula  lutea.  Frequently  the  vessels  branch  oiF  deeper  in  the 
optic  nerve,  and  make  their  first  appearance  at  the  temporal 
margin  of  the  disc.  In  general  the  individual  diflferences  in  the 
arrangement  of  the  vessels  depend  for  the  most  part  upon  whether 
the  point  at  which  they  are  given  off  is  visible  or  not. 

In  the  case  of  the  larger  retinal  vessels  it  is  easy  to  distinguish 
the  arteries  from  the  veins.  The  arteries  are  of  a  bright-red 
color;  the  veins  are  darker  and  often  somewhat  wider.  The 
arteries,  moreover,  generally  run  much  straighter  than  the  veins, 
which  latter,  even  under  physiological  relations,  are  often  remark- 
ably sinuous.  Along  the  centre  of  the  larger  retinal  vessels  is  seen 
a  bright  stripe,  the  reflex  from  the  cylindrical  wall,  more  apparent 
on  the  arteries  than  on  the  veins.  In  many  cases,  even  under 
physiological  conditions,  the  adventitial  coat  of  the  vessels  can  be 
seen  as  a  dull  white  line,  accompanying  the  principal  trunks,  both 
of  the  arteries  and  the  veins.  It  can  generally  be  seen  most  dis- 
tinctly in  the  upright  image,  but  it  is  very  seldom  that  it  can  be 
traced  upon  the  retina  beyond  the  limits  of  the  optic  disc. 

The  venous  pulsation  is  a  remarkable  physiological  phenome- 
non, frequently  present,  but  not  always  easily  seen.  LTpou  one  or 
another  of  the  larger  veins  at  a  place  where  it  curves  to  sink  into^ 
the  optic  nerve,  or  in  general  at  places  where  it  experiences  a 
sudden  curv^ature,  for  instance,  on  the  margin  of  a  physiological 
excavation,  a  short  portion  of  the  vein  can  be  seen  in  regular 
rhythm  alternately  to  collapse  and  then  become  distended  with 
blood.  The  collapse  begins  at  the  central  part  of  the  vein,  in 
advance  of  the  radial  pulse,  very  seldom  extends  to  the  limit  of 
the  optic  disc,  and  never  beyond  it  into  the  region  of  the  retina- 
The  dilatation  proceeds  quickly  from  the  periphery  toward  the 
centre,  and  follows  immediately  after  the  radial  pulse.  There  is 
a  short  pause  at  the  maximum  of  dilatation,  when  the  phenome- 
non repeats  itself  anew. 

This  symptom  was  explained  by  Donders*  in  the  following 

*  Arch.  f.  Ophth.,  B.  i.  2,  pag.  75. 
27 


410  '        ARTERIAL    PULSATION. 

manner.  The  augmented  pressure  with  which  the  blood  streams 
into  the  arteries  is  partially  propagated  to  the  vitreous  body 
before  it  has  had  time  to  extend  through  the  capillaries  into  the 
veins.  The  pressure  of  the  blood  in  the  veins  decreases  from 
the  capillaries  toward  the  heart,  and  accordingly  the  augmented 
pressure  in  the  vitreous  body  meets  with  the  least  resistance  from 
the  principal  venous  trunks  just  at  the  point  where  they  leave 
the  interior  of  the  eye.  This  portion  of  the  vein  is  therefore 
compressed,  and  its  contents  quickly  forced  out,  while  the  blood 
streaming  from  the  capillaries  is  dammed  up  on  the  distal  side 
of  the  compressed  portion.  After  the  ending  of  the  heart's 
systole  the  augmented  pressure  in  the  arteries  and  that  in  the 
vitreous  body  dependent  upon  it  intermit,  the  compression  of  the 
veins  ceases,  and  the  obstructed  blood  flows  rapidly  away.  If  the 
intraocular  pressure  be  increased  by  lightly  laying  the  finger  on 
the  eye,  the  venous  pulsation  may  be  produced  where  it  was  not 
formerly  seen,  or  if  it  was  seen,  is  thus  made  more  apparent. 

Pulsations  may  also  be  observed  in  the  arteries,  as  was  first 
demonstrated  by  E.  v.  Jaeger.*  The  most  striking  and  longest 
known  phenomenon  of  this  sort  is  the  so-called  arterial  })ulsation 
of  the  central  artery  of  the  retina.  An  impulse  in  the  red  column 
of  blood  in  the  trunk  of  the  artery  is  seen  at  the  time  of  the 
heart's  systole,  while  during  the  heart's  diastole  the  pulsating 
artery  appears  empty.  This  phenomenon  is  never  noticed  beyond 
the  limits  of  the  optic  disc,  and  very  seldom  extends  to  the  first 
division  of  the  arterial  branches. 

This  arterial  pulsation  never  occurs  except  when  the  pressure 
in  the  vitreous  body  is  greater  than  the  lateral  pressure  in  the 
arteries,  so  that  it  is  only  by  the  sudden  increase  of  the  arterial 
pressure  during  the  iieart's  systole  that  tlie  blood  can  penetrate 
the  arteries. 

This  phenomenon  can  be  observed  at  any  time  in  the  normal 
eye,  since  the  arterial  pulsation  may  always  be  produced  by  a 
steady,  uicreasing  pressure  of  the  finger  upon  the  eye.  During 
this  experiment  the  vessels  will  at  first  be  seen  to  contract  grad- 
ually, and  soon,  Avithout  the  pressure  being  at  all  unpleasant,  the 
pulsatio,ns  a^jpear.     The  arteries  become  empty  during  the  heart's 

*  Wiener  med.  Wochenschrift,  1854,  No.  3  bis  5. 


ARTEEIAL    PULSATION.  411 

diastole,  and  during  each  systole  the  blood  is  seen  to  stream  swiftly 
in  again.  Under  this  moderate  pressure  the  emptying  of  the  ves- 
sels occupies  about  one-third  and  their  filling  about  two-thirds 
of  th€  entire  rhythm.  Meanwhile  the  veins,  especially  upon  the 
optic  disc,  are  relatively -empty,  and  only  seldom  show  pulsations. 
If  exceptionally  a  simultaneous  venous  pulsation  be  visible,  the 
distention  of  the  veins  coincides  in  time  with  the  contraction  of 
the  artery. 

As  the  pressure  increases,  the  diastole  of  the  arteries  grows 
shorter.  Immediately  after  follows  the  distention  of  the  veins. 
It  appears  as  if  the  positive  wave,  when  the  pressure  is  so  great, 
were  propagated  more  rapidly  into  the  veins,  so  that  the  blood 
streams  almost  simultaneously  in  through  the  arteries  and  out 
through  the  veins. 

Finally,  during  the  greatest  pressure,  which,  however,  is  scarcely 
painful,  all  movement  of  the  blood  ceases;  the  positive  circulatory 
wave  can  no  longer  overcome  the  pressure  on  the  external  surfaces 
of  the  arteries. 

Simultaneously  with  these  changes  in  the  circulation  there  comes 
on,  while  the  pressure  of  the  finger  upon  the  outer  side  of  the  eye- 
ball is  gradually  increased,  a  darkening  of  the  visual  field.  Objects 
appear  at  first  obscured,  and  as  the  pressure  increases  they  disap- 
pear entirely.  This  darkening  follows  a  few  seconds  after  the 
appearance  of  the  arterial  pulse,  and  is  due  to  the  obstructed  cir- 
culation and  to  the  arrested  chemical  metamorphosis  dependent 
upon  it,  from  which,  as  Donders*  remarks,  it  seems  plainly  enough 
to  follow  that,  even  in  the  retina,  the  physical  eifect  of  light  be- 
comes a  chemical  one.  Upon  removing  the  pressure  the  disturb- 
ance of  vision  ceases  almost  immediately,  so  that  after  a  few  seconds 
it  is  no  longer  noticed. 

Arterial  jjulsation,  appearing  spontaneously,  always  shows  an 
abnormal  relation  between  the  blood  pressure  in  the  arteries  and 
the  intraocular  pressure.  In  most  cases  it  is  due  to  the  increase 
of  pressure  which  characterizes  glaucoma.  It  is  only  seldom  that 
the  opposite  condition  obtains, — that  is,  an  arterial  pressure  so 
decreased  that  it  is  too  weak  to  overcome  the  normal  intraocular 
pressure. 

*  Arch.  f.  Ophth.,  B.  i.  2,  pag.  101. 


412  PHYSIOLOGICAL   OPACITY   OF   RETINA. 

Arterial  pulsation  may  be  caused  by  a  mechanical  obstruction 
in  the  circulation,  by  w^hich  the  current  in  the  central  artery  of 
the  retina  is  retarded.  Among  such  obstructions  are  intraorbital 
tumors,  inflammatory  swelling  of  the  optic  nerve,*  or  too  weak 
an  action  of  the  heart,  like  that  preceding  a  faihting-fit.t 

The  rhythmical  streaming  in  of  the  blood,  and  the  change  in  the 
condition  of  the  artery,  which  is  alternately  empty  or  nearly  so, 
and  then  distended  with  blood,  give  to  the  arterial  pulse  a  thor- 
oughly pathological  character;  still,  there  occur  in  the  central 
retinal  artery  other  phenomena  of  pulsation  more  physiological 
in  their  nature.  Quincke^  first  pointed  out  the  fact  that  with  in- 
sufficiency of  the  aortic  valves  a  strong  distention  of  the  retinal 
arteries  simultaneously  with  the  heart's  systole  is  seen,  far  be- 
yond the  limits  of  the  optic  disc.  One  sees  not  only  a  lateral  dis- 
tention of  the  vessels,  but  at  the  same  time  an  elongation  of  the 
arteries,  which  is  expressed  by  an  increase  of  all  their  curvatures. 
O.  Becker,§  who  confirmed  this  fact  in  a  series  of  cases  of  aortic 
insufficiency,  observed,  at  the  same  time,  in  a  perfectly  normal  eye 
of  a  person  not  affected  with  heart  disease,  an  unmistakable  rhyth- 
mical swelling  and  movement  of  the  arteries  upon  the  disc  and 
retina.  Becker,  moreover,  confirmed  the  observation  made  by 
Quincke,  that  in  aortic  insufficiency  a  uniform  systolic  blush  and 
diastolic  paling  of  the  optic  disc  analogous  to  the  capillary  pulsa- 
tion to  be  seen  in  the  finger-nails  can  be  observed  in  the  upright 
image. 

In  its  normal  condition  the  retina  is  exceedingly  transparent, 
and  reflects  but  little  light.  The  brighter  the  color  of  the  cho- 
roid, the  more  light  is  reflected  from  it  and  from  the  sclera,  and 
so  much  the  less  visible  is  the  weak  reflex  from  the  retina.  If, 
however,  the  choroid  be  darkly  pigmented,  the  light  reflected  from 
the  retina  is  plainly  visible  against  this  dull,  dark  background, 
and  this,  of  course,  most  at  the  place  where  the  retina  is  thickest, 
that  is,  at  the  place  of  entrance  of  the  optic  nerve.     With  proper 

*  Only  three  cases  of  this  kind  are  reported.    See  Y.  Graefe,  Arch.  f.  Ophth., 
B.  xii.  2,  pag.  131. 

f  An  observation  by  Wordsworth,  Ophth.  Hosp.  Rep.,  iv.  pag.  111. 
+  Berl.  klin.  Wochenschrift,  1868,  No.  34,  and  1870,  No.  21. 
^  Arch.  f.  Ophth.,  B.  xviii.  1,  pag.  206. 


MACULA    LUTE A.  413 

illumination, — that  is,  in  the  examination  in  the  upright  image 
with  a  weak  mirror,  or  in  the  inverted  image  using  diffuse  daylight, 
— the  retina  can  generally  be  seen  near  the  optic  disc,  as  a  thin, 
light-gray  membrane.  This  physiological  opacity  of  the  retina 
may  be  so  great  as  to  become  evident  by  artificial  illumination, 
and  to  hide  the  boundary-line  of  the  optic  disc,  especially  on  its 
median  side.  Occasionally  in  such  cases  certain  of  the  retinal 
vessels,  where  they  run  for  a  distance  behind  the  nerve-fibre  layer, 
appear  lightly  veiled. 

That  margin  of  the  optic  disc  which  is  turned  toward  the  yellow 
spot  always  remains  free  from  this  clouding. 

This  appearance  in  the  retinal  substance  is  different  from  a 
peculiar  reflection  from  the  inner  surface  of  the  retina,  which  is 
often  seen  in  the  inverted  image  in  children,  and  more  rarely  in 
adults,  and  which  is  generally  visible  over  a  great  part  of  the 
retina.  This  is  a  diffuse,  glistening  reflex,  which  changes  its  posi- 
tion as  the  mirror  is  moved,  and  which  generally  can  be  followed 
farthest  toward  the  periphery  along  the  course  of  the  retinal  ves- 
sels. This  reflection  from  the  retina,  when  present,  shows  a  very 
peculiar  and  characteristic  behavior  in  the  region  of  the  macula 
lutea;  it  ends  here  abruptly,  with  a  sharply  defined  boundary;  it 
is  wholly  absent  or  is  very  weak  at  the  macula  lutea,  which  thus 
appears  as  if  surrounded  by  a  glittering  ring,  whose  diameter  is 
somewhat  greater  than  that  of  the  optic  disc,  and  which,  by  a 
slight  movement  of  the  mirror,  may  be  distinctly  traced  in  its 
entire  circumference. 

It  appears  most  natural  to  refer  this  reflex  to  the  connective 
tissue  of  the  retina,  particularly  of  the  nerve-fibre  layer.  This 
is  known  to  be  very  thin  in  the  region  of  the  yellow  spot,  and, 
moreover,  Miiller's  radiating  fibres,  which  are  attached  by  broad 
extremities  to  the  internal  limiting  membrane,  though  not  ab- 
solutely wanting  at  the  macula  lutea,  are  so  thin  that  they  can 
be  microscopically  demonstrated  only  with  great  difficulty.  Of 
course  there  must  be  certain  individual  peculiarities  which  cause 
this  reflex  to  be  only  occasionally  visible.  Mauthner  directed 
attention  to  the  remarkable  fact  that  this  reflex  is  wholly  absent 
in  the  upright  image. 

In  many  cases,  and  even  in  such  as  do  not  show  the  above 
described  reflex,  the  centre  of  the  macula  lutea  is  prominent  by 


414  MACULA    LUTEA. 

reason  of  its  red  color.  The  fovea  centralis  is  recognized  as  a 
small  red  disc,  whose  centre  often  appears  as  a  whitish,  round,  or 
sometimes  hook-shaped  spot.  This  spot  is  perhaps  only  to  be 
regarded  as  a  reflex,  since  the  centre  of  the  fovea  centralis  is 
better  adapted  than  are  its  steep  walls  to  reflect  light  in  the  direc- 
tion of  the  visual  axis.  The  red  color  of  the  fovea  centralis,  as 
well  as  that  of  the  fundus  in  general,  can  be  due  only  to  the 
blood  of  the  choroid ;  and  the  fact  that  this  color  is  a  darker  red 
in  the  region  of  the  fovea  centralis  may  be  partly  explained  by 
the  darker  pigmentation  which  always  exists  in  the  choroidal 
epithelium  in  the  region  of  the  macula  lutea,  on  account  of 
which,  especially  in  a  light-colored  stroma,  this  portion  presents 
a  deep-red  color.  Moreover,  this  color  is  so  much  the  more 
distinct  for  the  reason  that  the  fovea  centralis  is  a  circumscribed 
depression,  upon  whose  floor  the  retina  is  much  thinner  than  upon 
the  immediately  adjoining  portions  of  the  yellow  spot.  Generally, 
in  the  cases  in  which  the  fovea  centralis  is  ophthalmoscopically 
distinct,  the  above  described  slight  physiological  opacity  of  the 
retina  can  be  seen  in  the  inverted  image,  and  by  daylight  extend- 
ing up  to  the  fovea  centralis,  but  wanting  within  it.  This  also 
proves  that  the  red  color  of  the  choroid  is  somewhat  softened  by 
the  retina,  and  that  it  is  only  because  the  retina  at  this  place  is 
thinner  that  the  fovea  centralis  appears  so  distinctly. 

The  examination  by  daylight  shows,  moreover,  that  the  yellow 
color  of  the  macula  lutea  is  only  a  post-mortem  appearance;  if 
the  retina  surrounding  the  fovea  centralis  exhibit  any  color,  it  is 
always  a  light  gray,  and  never  a  bright  yellow.  Such  a  bright 
yellow,  if  it  were  present  during  life,  could  not  possibly  escape 
observation  during  the  ophthalmoscopic  examination  by  daylight, 
which  admits  of  so  distinct  a  recognition  of  all  colors. 

Frequently  the  macula  lutea  presents  none  of  the  above  described 
appearances.  Only  its  position  is  then  indicated,  and  that,  by  the 
manner  in  which  the  retinal  vessels  taper  to  a  point  and  appear 
to  end  about  it. 

The  examination  of  the  macula  lutea  is  more  difficult  than  that 
of  any  other  portion  of  the  fundus,  since,  in  the  first  place,  the 
pupil  contracts  very  suddenly  when  the  light  is  directed  upon  this 
most  sensitive  part  of  the  retina ;  and,  secondly,  the  unavoidable 
corneal  reflex  covers  a  part  of  the  already  contracted  pupil. 


PIGMENTATION   OF    THE    CHOROID.  415 

When  these  optical  difficulties  are  overcome  by  the  use  of  atro- 
pine, the  macula  lutea  is  most  easily  found,  both  in  the  upright 
and  in  the  inverted  image,  by  finding  first  the  optic  disc,  and  then 
proceeding  outward  from  its  temporal  margin. 

In  cases  in  which  the  fovea  centralis  is  not  especially  distinct, 
and  where  it  is  desired  to  examine  this  region  carefully,  it  is  best 
to  examine  in  the  upright  image  with  a  weak  mirror,  and  to  cause 
the  patient  to  look  directly  at  the  flame  reflected  from  the  mirror. 

At  the  periphery,  the  retina  is  so  thin  and  transparent  that  it 
can  be  recognized  by  the  presence  of  its  vessels  only. 

Under  pathological  conditions,  however,  and  most  frequently 
from  detachment  of  the  retina,  its  peripheral  part  may  become 
so  opaque  as  to  be  distinctly  seen. 

The  choroid  in  its  natural  condition,  on  account  both  of  its 
pigment  and  of  its  great  vascularity,  exercises  an  important  influ- 
ence upon  the  ophthalmoscopic  image,  and  upon  the  color  of  the 
fundus. 

The  retina  is  almost  absolutely  transparent,  the  sclera  is  covered 
by  the  choroid,  and  can  be  illuminated  and  seen  only  through  it. 
The  more  pigment  the  choroid  contains,  the  less  noticeable  in  the 
ophthalmoscopic  image  is  the  white  sclera  shining  through  it. 

But  the  appearance  of  the  choroid  itself  varies  according  to  the 
amount  of  pigment  contained  in  it. 

The  character  of  the  pigment  epithelium  is  of  great  influence. 
Although  it  consists  of  but  a  single  layer  of  cells,  it  is  still  very 
opique,  and  when  possessing  its  normal  quantity  of  pigment  it 
almost  wholly  hides  the  choroidal  stroma  lying  behind  it.  This 
can  be  easily  demonstrated  anatomically  by  comparing,  under  a 
weak  magnifying  glass,  a  portion  of  the  choroid  still  covered  by 
its  epithelium  with  another  portion  from  which  the  epithelium 
has  been  removed. 

The  great  absorption  of  light  in  the  choroidal  epithelium  is  the 
cause  why,  when  the  pigment  is  very  dense,  so  little  can  be  seen 
of  the  choroidal  stroma.  In  such  a  case  the  retinal  vessels  are 
seen  to  branch  over  a  quite  uniformly  colored  red  background. 

Nevertheless,  the  amount  of  pigment  in  the  choroidal  epi- 
thelium varies  considerably  in  diflferent  individuals,  but  the  color 
of  this  epithelial  layer  over  the  entire  fundus,  so  far  as  can  be 


416  INTER  VASCULAR   SPACES    OF   THE    CHOROID. 

seen,  is  in  any  given  case  uniform,  except  that  in  the  region  of  the 
macula  lutea  the  epithelium  is  always  darker. 

In  new-born  infants  the  pigment  epithelium  is  always  very 
dark,  while  the  stroma  is  of  a  lighter  color. 

In  many  cases,  especially  with  relatively  slight  pigmentation  of 
the  choroidal  stroma,  the  fundus  presents  a  granular,  shagreen 
appearance,  generally  most  distinct  at  the  equatorial  part.  It  is 
certain  that  this  punctation,  which  has  no  pathological  signifi- 
cance, must  be  referred  to  the  epithelial  layer  of  the  choroid.  But 
the  possibility  asserted  by  Liebreich,*  of  recognizing  ophthalmo- 
scopically  the  individual  cells  of  the  choroidal  epithelium,  is  doubt- 
ful. The  superficial  diameter  of  a  single  cell  is  0.013  to  0.016 
mm.  Substituting  these  figures  in  the  calculation  made  on  page 
102,  each  cell  in  the  upright  image  would  appear  included  within 
a  visual  angle  of  about  3  minutes. 

Now,  it  is  true,  according  to  Tob.  Mayer,t  that  checker-board- 
like  figures  can  be  recognized  under  a  visual  angle  of  only  a  little 
more  than  2  minutes ;  but  the  uniform,  closely  placed  epithelial 
cells  of  the  choroid  are,  even  with  ophthalmoscopic  illumination, 
far  less  favorable  objects. 

If  the  choroid,  both  in  its  epithelium  and  in  its  stroma,  be 
weakly  pigmented,  its  vascular  net-work  is  the  more  apparent. 
The  choroidal  vessels,  even  to  their  finest  ramifications,  are  dis- 
tinctly visible  against  the  background  formed  by  the  sclera.  The 
vascular  trunks  of  the  vense  vorticosae  which  penetrate  the  sclera, 
also  appear  with  equal  distinctness,  and  of  surprising  size.  Eyes 
affected  with  this  slight  degree  of  albinismus  are  generally  my- 
opic, and  not  sharp-sighted.  Higher  grades  of  albinismus,  with 
complete  absence  of  pigment  in  the  epithelium  and  in  the  stroma 
cells,  are  always  connected  with  nystagmus. 

The  image  of  the  fundus  of  the  eye  is  very  different  when  the 
choroidal  stroma  is  rich  in  pigment,  while  the  epithelium  has  but 
little  and  is  therefore  transparent.  Here  the  large  vascular 
trunks  lying  in  the  outermost  layers,  and  their  finest  branches 
as  well,  are  hidden  by  the  pigment  of  the  stroma,  while  the  vessels 
of  medium  size  remain  visible,  forming  a  distinct  red  net-work. 


*  Arch.  f.  Ophth.,  B.  iv.  2,  pag.  486. 

f  Helmholtz,  Physiologische  Optik,  pag.  218. 


INTERVASCULAR   SPACES    OF   THE    CHOROID.  417 

whose  meshes,  the  so-called  intervascular  spaces,  a})pear  almost 
black  on  account  of  the  darkness  of  the  stromal  pigment. 

The  form  of  these  intervascular  spaces  varies  according  to  their 
locality.  In  the  deeper  parts  of  the  fundus,  in  the  region  of  the 
optic  disc  and  macula  lutea,  the  net-work  of  the  choroidal  vessels  is 
closer,  and  the  intervascular  spaces  therefore  more  rounded  at  the 
corners.  In  the  equatorial  part  the  choroidal  vessels  run  more  in 
a  meridional  direction,  and  with  fewer  anastomoses;  consequently 
the  intervascular  spaces  are  elongated. 

Frequently  the  consequences  above  explained,  of  a  very  dark 
pigmentation  of  the  choroidal  stroma  with  a  relatively  light  pig- 
mentation of  the  epitiielium,  are  so  marked,  and  produce  an 
ophthalmoscopic  image  so  different  from  the  usual  one,  that  the 
beginner  is  often  inclined  to  regard  the  dark  intervascular  spaces 
upon  the  red  background  as  pathological.  Such  an  error  may 
be  guarded  against  by  observing  the  differences  of  form  of  these 
dark  intervascular  spaces  dependent  upon  their  position  in  the 
fundus,  and  the  uniformity  with  which  this  peculiar  pigmentation 
is  diffused  over  the  fundus. 

If,  on  the  contrary,  the  vessels  and  intervascular  spaces  of  the 
choroid  be  much  more  distinct  at  certain  places  than  at  others, 
there  is  reason  to  assume  that  there  is  a  local  loss  of  pigment  in 
the  epithelium  at  those  places  where  the  choroidal  stroma  is  most 
apparent. 

Of  course,  from  pathological  causes,  the  epithelium  over  a 
large  portion  of  the  choroid  may  lose  its  pigment,  and  present 
thereby  the  above  mentioned  ophthalmoscopic  picture.  If  simul- 
taneously there  exist  other  changes,  for  instance,  pigmentation 
of  the  retina,  there  can  be  no  doubt  concerning  the  process.  In 
the  absence  of  other  visible  choroidal  changes,  the  only  circum- 
stance to  indicate  that  this  is  a  pathological  discoloration  of  the 
choroidal  epithelium  is  that  this  ophthalmoscopic  picture  is  rela- 
tively frequently  observed  in  connection  with  certain  pathological 
processes,  for  instance,  with  a  protracted  increase  of  the  intraocular 
pressure  in  darkly  pigmented  eyes. 


DISEASES  OF  THE  CHOROID. 


Hyper^emia  of  the  choroid  frequently  occurs  in  connection 
with  inflammatory  processes  in  the  vascular  coat  of  the  eye,  and 
probably  also  as  an  independent  chronic  condition.  This  condition, 
however,  cannot  be  diagnosticated  with  any  certainty.  The  distinct- 
ness with  which  the  choroidal  vessels  are  seen  ophthalmoscopically, 
as  well  as  the  color  of  the  fundus  of  the  eye  in  general,  dej^ends 
upon  the  color  and  quantity  of  the  pigment  both  in  the  choroidal 
epithelium  and  in  its  stroma,  and  aside  from  this,  upon  the  intensity 
of  the  ophthalmoscopic  illumination,  which,  assuming  an  unvary- 
ing source  of  light  and  complete  transparency  of  the  refracting 
media,  depends  principally  upon  the  size  of  the  pupil.  The  pos- 
sible combinations  of  all  these  factors  are  too  numerous  to  admit 
the  possibility  of  determining  from  the  ophthalmoscopic  appear- 
ance of  the  choroid  whether  it  contains  more  or  less  than  the 
normal  quantity  of  blood.  The  ap])earance  of  the  optic  disc  fur- 
nishes a  more  reliable  criterion,  its  increased  redness  indicating  a 
collateral  hypersemia,  but  even  from  this  appearance  no  certain 
conclusion  can  be  drawn. 

Hyperaemia  of  the  choroid,  therefore,  is  a  condition  which  can- 
not be  absolutely  demonstrated,  but  whose  existence  or  absence  is 
rather  to  be  inferred  fri:;m  the  circumstances  of  each  particular  case. 

CYCLITIS. 

It  can  be  easily  understood  from  the  continuity  of  tissue  in  the 
iris,  ciliary  body,  and  choroid  that  the  inflammatory  processes  in 
these  three  portions  of  the  vascular  coat  cannot  be  sharply  defined 
one  from  another.  Opacities  of  the  vitreous  frequently  remain 
after  iritis,  i)roving  that  the  inflammation  was  by  no  means  limited 
to  the  iris.  On  the  other  hand,  we  observe  ophthalmoscopically 
acute  choroiditis  in  connection  with  iritis;  or  an  iritis  is  grad- 
ually developed  in  the  course  of  a  chronic  choroiditis. 

We  must  certainly  assume  that  the  extension  of  such  an  in- 
418 


CYCLITIS.  419 

flaimiiatory  process  is  through  the  ciliary  body,  but  it  is  ouly 
seldom  that  the  changes  within  this  part  are  so  considerable,  and 
the  symptoms  to  be  referred  to  this  complication  so  decided,  as 
those  described  upon  page  344  as  characteristic  of"  irido-cyclitis. 

There  is  still  greater  difficulty  in  recognizing  an  inflammation 
which  begins  in  the  ciliary  body,  for  this  part  can  neither  be  seen 
directly  nor  with  the  ophthalmoscope,  and  the  tenderness  upon 
pressure  is  not  an  absolutely  reliable  symptom.  If,  however,  we 
observe  severe  j)ain,  with  decided  hyperemia  of  the  subconjunc- 
tival vessels  at  the  margin  of  the  cornea,  without  any  visible  cor- 
responding changes  in  the  iris,  while  after  the  lapse  of  an  acute 
inflammatory  })eriod,  opacities  are  visible  in  the  anterior  portion 
of  the  vitreous  body,  we  are  certainly  justified  in  regarding  the 
process  as  cyclitis.     Frequently  iritis  comes  on  at  a  later  stage. 

In  another  class  of  cases,  after  there  have  been  for  some  days 
moderate  photophobia,  pain  when  using  the  eyes,  an  inclination  to 
deep  subconjunctival  hypersemia,  and  disturbance  of  vision,  due 
to  slight  opacity  of  the  vitreous,  there  develops  a  small  hypopion, 
which  must  be  regarded  as  coming  from  the  ciliary  body,  since 
there  is  no  apparent  disease  of  the  cornea  or  iris.  In  its  further 
course  this  hypopion  generally  disappears  and  reappears  repeatedly, 
while  the  opacities  of  the  vitreous  increase  and  vision  greatly 
diminishes. 

Both  forms  of  cyclitis  are  very  rare.  They  may  occur  without 
any  apparent  cause. 

The  fact  that  the  diseases  of  the  uveal  tract  are  not  sharply 
defined,  but  pass  one  into  another,  is  well  illustrated  by  those 
inflammations  of  the  eye  which  occur  as  sequelae  of  recurrent  fever. 
The  most  recent  observers  agree  as  to  their  essential  nature,  but 
some  describe  them  as  irido-choroiditis,  some  as  cyclitis. 

The  cases  which  were  observed  during  an  epidemic  of  recur- 
rent fever  in  the  Charite  Hospital  in  Berlin,  occurred  mostly  after 
the  second  or  third  attack  of  fever,  which  then  generally  proved 
the  last.  Nearly  half  the  cases  were  simple  unilateral  iritis  of  a 
moderate  grade.  About  one-third  of  the  patients  presented  diffuse 
punctiform  or  flocculent  floating  opacities  of  the  vitreous,  without 
any  trace  of  iritis,  and  without  any  external  symptoms  of  disease, 
while  the  remainder  of  the  cases  presented  iritis  with  ojjacities  of 
the  vitreous.     In  the  great  majority  of  cases  only  one  eye  Avas 


420  CHOROIDITIS. 

affected .  On  the  whole,  the  disease  ran  a  very  mild  course.  The 
external  symptoms  of  inflammation  were  moderate,  and  only  ex- 
ceptionally was  there  any  chemotic  swelling  of  the  conjunctiva. 
The  treatment  was  limited  to  the  use  of  atropine,  except  in  the 
cases  where  dense  opacities  of  the  vitreous  existed,  when  iodide 
of  potassium  and  diuretics  were  resorted  to.  Of  course,  as  the 
patients  were  greatly  reduced,  a  nutritious  diet  was  provided. 

Other  epidemics  of  recurrent  fever  appear  to  be  followed  by 
more  severe  disease  of  the  eyes.  The  objective  symptoms  are 
great  hypersemia  at  the  margin  of  the  cornea,  chemotic  swelling 
of  the  conjunctiva,  fine  punctiform  deposits  upon  the  posterior 
wall  of  the  cornea,  hypopion,  dense  opacity  of  the  vitreous,  and 
frequently  an  abnormal  softness  of  the  eye.  Slight  amblyopia, 
with  posterior  polar  cataract  or  opacities  of  the  vitreous,  or  with 
changes  in  the  pigment  of  the  anterior  portion  of  the  choroid,  has 
been  observed  to  remain  behind.  Blindness  rarely  ensues,  and 
when  it  does,  is  a  consequence  of  iritis  with  annular  adhesion  of 
the  margin  of  the  pupil  or  of  detachment  of  the  retina,  or  ex- 
ceptionally of  suppuration  of  the  cornea. 

We  have  here  a  form  of  disease  whose  etiology  is  very  clearly 
defined,  and  which  affects  the  uveal  tract,  but  it  localizes  itself 
sometimes  on  one  portion  and  sometimes  on  another,  and  the 
degree  of  its  intensity  varies  greatly. 

CHOROIDITIS. 

Purulent  choroiditis  is  the  most  severe  form  of  choroidal  in- 
flammation. It  generally  involves  the  entire  eye,  and  the  name 
panophthalmitis,  therefore,  well  describes  this  condition. 

The  lids  are  swollen  and  reddened,  the  entire  conjunctiva  is  in- 
filtrated, there  is  a  purulent  secretion  in  the  conjunctival  sac,  the 
cornea  is  clouded,  the  iris  discolored  and  adherent  to  the  capsule 
of  the  lens,  the  aqueous  humor  is  clouded,  and  often  contains 
flocculent  coagula  or  a  copious  purulent  sediment.  In  conse- 
quence of  the  swelling  of  the  orbital  tissues,  the  eye  is  prominent 
and  its  movements  are  difficult.  Vision  is  in  a  short  time  com- 
pletely lost  or  reduced  to  a  slight  perception  of  light.  From  the 
very  first  there  are  generally  severe  pains,  which  may  last  during 
the  whole  course  of  the  disease  ;  in  some  cases,  however,  the  pain 
is  very  slight. 


PURULENT    CHOROIDITIS.  421 

The  disease  is  frequently  accompanied  by  vomiting,  and  in 
severe  cases  by  fever. 

The  pus  accumulated  within  the  eyeball  generally  breaks 
through.  This  occurs  in  the  cornea  when  that  has  likewise  been 
destroyed  by  suppuration,  or  when  the  cornea  remains  intact  the 
rupture  is  in  the  sclera.  In  milder  cases,  in  which  the  pus  does 
not  break  through,  there  follow,  with  all  the  signs  of  chronic 
irido-choroiditis,  an  opacity  of  the  lens  and  more  or  less  atrophy 
of  the  eyeball. 

The  disease  is  most  frequently  of  traumatic  origin,  being  caused 
by  wounds,  unfortunate  operations,  foreign  bodies  in  the  eye,  etc. 
The  same  result  may  be  caused  by  ulceration  of  the  cornea,  with 
prolapse  and  purulent  inflammation  of  the  iris. 

A  very  slight  provocation  may  excite  a  purulent  choroiditis  in 
an  eye  already  suffering  from  a  chronic  internal  inflammatory 
trouble,  such  as  choroiditis  or  retinal  detachment,  or  the  pres- 
ence of  a  cysticercus. 

Embolism  is  another  very  noticeable  cause.  It  occurs  most 
frequently  in  puerperal  diseases,  but  anything  which  causes  em- 
bolism may  also  induce  purulent  choroiditis.  It  is  remarkable 
that  in  the  choroiditis  caused  by  embolism,  at  least  in  the  puerperal 
form,  it  sometimes  happens  that  both  eyes  are  affected,  one  shortly 
after  the  other. 

Anatomically,  the  condition  is  one  of  hemorrhagic  purulent 
inflammation. 

The  pus-corpuscles  in  the  stroma  of  the  choroid  are  at  first 
always  most  numerous  in  the  immediate  neighborhood  of  the 
chorio-capillaris;  if  the  suppuration  be  more  profuse,  the  entire 
stroma  becomes  filled  with  corpuscles,  between  which  the  branch- 
ing pigment  cells  are  crowded  together  in  parallel  anastomosing 
lines.  In  many  cases  the  choroidal  stroma  is  greatly  thickened 
by  the  inflammatory  exudate  and  its  inner  surface  thrown  into 
irregular  prominences. 

The  pigmented  stroma  cells  mostly  remain  unchanged ;  still 
they  sometimes  undergo  fatty  degeneration  and  loss  of  color. 

The  pigment  epithelium  may  remain  normal,  or  may  suffer 
changes  in  spots  or  in  its  entire  extent.  These  changes  affect 
partly  the  form  and  partly  the  pigment  of  the  cells.  In  conse- 
quence of   their  growth  and  segmentation,  the  cells  assume  an 


422  PURULENT   CHOROIDITIS. 

irregular  form,  and  their  proliferation  may  become  excessive. 
Fatty  degeneration  of  the  pigment  epithelium  and  its  detachment 
from  the  surface  of  the  choroid  may  also  occur. 

The  ciliary  body  and  iris  participate  early  in  the  inflammatory 
process,  which  at  a  later  stage  assumes  a  purulent  character. 

The  retina  soon  becomes  involved.  H.  Meckel*  diagnosed  on 
the  second  day  of  the  inflammation  a  complete  softening  of  the 
retina  in  those  portions  lying  over  the  inflamed  parts  of  the 
choroid.  Later  there  was  hemorrhagic  purulent  retinitis  near  the 
optic  nerve  and  macula  lutea,  with  here  and  there  fast  adhesions 
between  the  retina  and  the  choroid,  caused  by  a  fibrinous  exudate, 
and  at  other  places  circumscribed  detachments  of  the  retina,  caused 
by  a  bloody  serous  fluid.  From  my  own  investigations,  I  can  also 
affirm  the  occurrence  of  hemorrhagic  purulent  retinitis  as  a  con- 
sequence of  purulent  choroiditis.  Still,  it  should  be  remarked 
that  in  the  puerperal  forms  which  were  examined  by  Meckel  the 
retinitis  may  be  caused  by  simultaneous  embolism  of  the  retinal 
vessels,  as  some  cases  of  Virchow's  have  proved. f 

At  a  later  stage,  total  detachment  of  the  retina  generally  fol- 
lows, and  the  exudate  collected  between  the  retina  and  the  choroid 
is  then  frequently  also  of  a  purulent  character. 

H.  Meckel  found  in  the  vitreous,  pus-corpuscles  and  prolifera- 
tion of  the  cells.  The  cloudiness  of  the  vitreous  observed  when 
the  disease  has  been  of  a  few  days'  duration,  and  which  appears 
to  consist  of  fine  granules  and  countless  interlacing  fibres,  he 
regarded  as  post-mortem  coagula ;  and  probably  he  is  right. 

The  sclerotic,  aside  from  slight  hemorrhages  upon  its  inner  or 
its  outer  surface,  is  at  first  unchanged ;  later,  however,  it  becomes 
thickened.  H.  Meckel  observed  a  thickening  as  early  as  the 
eleventh  day  of  the  choroiditis. 

When  panophthalmitis  is  once  established,  its  course  cannot  be 
checked.  The  object  of  the  treatment,  therefore,  is  simply  to 
make  the  condition  endurable,  and  to  soothe  the  pain.  Opiates, 
injections  of  morphine  into  the  temple,  and  M'arm  cataplasms  upon 
the  eye  are  the  most  useful  remedias. 

There  is  a  special  interest  attached  to  a  certain  form  of  irido- 

*  Annalen  der  Charite-Krankenhauses,  B.  v.  pag.  276. 

I  Arch.  f.  path.  Anat.,  B.  x.  pag.  181 ;  Ge.sammelte  Abhandl.,  pag.  719. 


ACrTE   IRIDO-CHOROIDITIS.  423 

choroiditis  on  account  of  its  connection  with  meningitis.  It  gen- 
erally occurs  during  the  first  days  or  weeks  of  that  disease.  It 
is  in  connection  with  cerebro-spinal  meningitis*  that  this  sad 
complication  most  frequently  occurs.  Iritis  develops  with  symp- 
toms of  irritation,  which  sometimes  are  at  first  slight,  but  often 
are  severe  from  the  beginning.  Adhesion  of  the  margin  of  the 
pupil  to  the  lens  immediately  occurs,  with  its  usual  consequences, 
such  as  the  driving  forward  of  the  periphery  of  the  iris,  etc. 
There  is  frequently  an  exudate  in  the  pupil,  or  there  is  hypopion. 
An  early  infiltration  of  the  vitreous  body  causes,  when  the  pupil 
is  still  transparent,  a  bright  reflex  from  the  fundus.  Detachment 
of  the  retina  and  atrophy  of  the  eyeball  are  the  usual  results.  It 
is  very  seldom  that  the  disease  runs  its  course  without  decided 
injury  to  vision,  and  without  leaving  slight  adhesions. 

Neuro-retinitis,  paralysis  of  the  ocular  muscles,  and  amblyopia 
may  also  be  mentioned  as  consequences  of  meningitis. 

The  connection  between  meningitis  and  the  diseases  of  the  eye 
may,  with  the  greatest  probability,  be  explained  by  the  direct 
connection  which  Schwalbef  has  shown  to  exist  between  the 
arachnoidal  lymph-space  and  the  lymph-spaces  of  the  eye. 

Acute  irido-clioroiditis  is  often  the  consequence  of  an  injury. 
Traumatic  choroiditis,  sooner  or  later,  generally  assumes  the  char- 
acter of  panophthalmitis ;  but  frequently,  with  all  the  symptoms 
of  a  severe  iritis,  there  follow  dense  opacity  of  the  vitreous, 
detachment  of  the  retina,  and  atrophy  of  the  eyeball. 

Acute  irido-choroiditis,  occurring  without  any  apparent  cause 
in  hitherto  healthy  eyes,  is  exceedingly  rare.  In  addition  to  the 
signs  of  a  severe  acute  iritis,  with  or  without  purulent  and  fibrin- 
ous exudations  in  the  anterior  chamber,  there  appears  a  diffuse 
or  flocculent  clouding  of  the  vitreous,  with  considerable  dimi- 
nution of  vision.  The  usual  treatment  is  bv  stronsr  antiphloo'is- 
tics  and  rapid  mercurialization.     Dobrowolski|  observed  in  two 


*  Salomon,  Berl.  klin.  Wochenschrift,  1864,  No.  33;  Knapp,  Centralblatt 
fiir  die  med.  Wissensch.,  186-5,  No.  33;  Kreitmeier,  Aertzliches  Intelligenz- 
blatt  fill-  Bayern,  1865,  Nos.  21  und  22;  Jos.  Jacobi,  Arch.  f.  Ophth.,  B.  xi. 
3,  pag.  157;  Schirmer,  Klin.  Monatsbl.  f.  Augenheilk.,  1865,  pag.  275. 

t  Untersuchungen  iiber  die  Lymphbahnen  des  Auges,  M.  Schultze's  Arch., 
B.  vi.  1870. 

X  Klin.  Monatsbl.,  1868,  pag.  239. 


424  ACUTE   CHOROIDITIS. 

such  cases  a  good  effect  from  repeated  puncture  of  the  anterior 
chamber. 

Just  as  chronic  irido-choroiditis  may  follow  iritis  with  annular 
adhesion  of  the  margin  of  the  pupil,  so,  too,  the  opposite  process 
may  take  place, — that  is,  iritis  may  supervene  upon  chronic  cho- 
roiditis. 

If  such  blind  or  nearly  blind  eyes  be  tlie  seat  of  severe  pain, 
a  i^  to  1  per  cent,  solution  of  morphine  dropped  into  them  gives 
often  great  relief.  The  immediate  local  effect  of  morphine  is,  it 
is  true,  irritating ;  but  this  soon  passes  away. 

Long-persisting  irido-choroiditis  may  cause  calcification  of  the 
lens,  or  extensive  calcareous  deposits  on  the  surface  of  the  choroid, 
or  an  irregular  thickening  or  ossification  of  the  lamina  vitrea. 
The  new-formed  osseous  tissue  generally  develops  between  the 
choroid  and  the  retina.  It  is  only  exceptionally  that  the  forma- 
tion of  bone  occurs  in  the  stroma  of  the  choroid. 

These  new-formed  bony  shells  are  generally  thickest  at  the  pos- 
terior part  of  the  choroid,  where  they  surround  the  optic  disc,  and 
are  penetrated  by  the  detached,  stretched,  and  distorted  retina. 
There  is  always  total  detachment  of  the  retina,  and  generally  also 
atroj)hy  of  the  eyeball.  Frequently  the  bony  shell  extends  so  far 
forward  that  it  may  be  recognized  by  palpation. 

The  ossification  generally  excites  a  continual  irritation,  with 
very  painful  exacerbations;  indeed,  it  may  even  give  rise  to  sym- 
pathetic affection  of  the  other  eye.  The  enucleation  of  the  eye 
is  therefore  indicated  as  soon  as  symptoms  occur  which  give  reason 
to  fear  this  complication. 

Another  class  of  cases,  partly  on  account  of  the  very  slight 
external  visible  changes,  and  partly  on  account  of  the  ophthalmo- 
scopic appearances,  are  characterized  as  acute  choroiditis.  There 
are  deep  pericorneal  injection,  hypersemia  of  the  iris  or  slight  iritis, 
frequently  also  punctated  opacities  on  the  inner  surface  of  the 
membrane  of  Descemet,  and  in  some  cases  deep-seated  pain  in 
the  eye ;  all  indicating  that  the  entire  vascular  coat  participates  in 
the  inflammatory  process. 

The  actual  centre  of  inflammation  is  generally  in  the  posterior 
part  of  the  choroid.  Frequently,  circumscribed,  whitish  masses 
of  exudate  may  be  observed  there,  hiding  the  choroid,  and  ele- 
vating slightly  above  the  surface  of  the  surrounding  parts  the 


ACUTE   CHOKOIDITIS.  425 

retinal  vessels  which  run  over  them.  At  a  later  period  black 
pigment  sjiots  frequently  develop  upon  this  exudate.  Generally 
there  is  a  dense  clouding  of  the  vitreous  from  the  very  beginning. 
This  may  diminish  in  the  course  of  time,  or  the  condition  may 
become  one  of  chronic  inflammation,  even  becoming  complicated 
with  cataract. 

In  another  class  of  cases  the  choroidal  exudate  seems  rather  to 
be  of  a  serous  character,  and  to  cause  an  infiltration  of  the  retina. 

At  first  a  somewhat  distinct  whitish  opacity  of  the  retina  is 
observed.  It  appears  to  be  mostly  in  the  external  layers,  since 
the  fine  retinal  vessels  can  be  seen  sharply  defined  against  this 
bright  background,  although  at  places  the  larger  vessels  also 
appear  to  be  hidden  by  slightly  clouded  retinal  substance.  A 
swelling  of  the  intraocular  extremity  of  the  optic  nerve  may  at 
the  same  time  occur,  and  is  all  the  more  likely  to  give  rise  to  an 
error  in  diagnosis  from  the  fact  that  at  this  stage  the  opacity  of 
the  retina  prevents  the  examination  of  the  choroid.  But  in  the 
course  of  a  few  weeks,  as  the  retina  clears  up,  the  choroidal 
changes,  which  consist  partly  in  discoloration  of  the  pigment 
epithelium  and  partly  in  the  formation  of  dark  pigment  patches, 
become  "visible.  The  principal  seat  of  these  changes  is,  in  the 
neighborhood  of  the  optic  nerve  and  macula  lutea;  still,  they 
appear  also  in  the  equatorial  parts  of  the  choroid.  Opacities  of 
the  vitreous  generally  do  not  exist,  or  are  very  slight. 

This  serous  infiltration  always  causes  a  decided  torpor  retinae; 
that  is,  retinal  images  can  be  perceived  only  by  very  intense  illu- 
mination, while  as  the  illumination  is  diminished  there  occurs  a 
disproportionate  diminution  of  retinal  sensitiveness.  This  torpor 
is  generally  most  decided  in  the  periphery  of  the  retina,  so  that  as 
the  illumination  diminishes  a  rapid  contraction  of  the  visual  field 
occurs. 

Serous  infiltration  of  the  macula  lutea  always  causes  a  considr 
erable  diminution  of  vision. 

Many  cases  of  choroiditis  run  their  course  without  giving  rise 
to  any  external  symptoms  of  inflammation,  and  can  therefore  be 
recognized  only  by  ophthalmoscopic  examination.  The  diagnosis 
is  based  in  all  cases  upon  the  changes  visible  in  the  choroidal  pig- 
ment; but  it  must  be  remembered,  on  the  one  hand,  that  by  no 

28 


426  CHOROIDITIS    DISSEMINATA. 

means  all  visible  choroidal  changes  are  of  inflammatory  origin, 
and,  on  the  other,  that  choroiditis  may  run  its  course  without 
leaving  noticeable  traces  in  this  membrane. 

In  one  class  of  cases  these  pigment  changes  are  uniformly  dissem- 
inated over  the  entire  choroid,  or  over  a  large  region  of  it;  another 
class  presents  the  peculiarity  that  a  immber  of  variously  shaped 
and  very  variously  colored  spots  lie  scattered,  island-like,  upon  an 
otherwise  normally  appearing  choroid  (choroiditis  disseminata). 

The  form  of  these  spots  is  generally  roundish  or  oval.  They 
are  generally  considerably  smaller  than  the  optic  disc;  still,  larger 
ones  do  occur,  or  several  such  spots  may  run  together,  forming 
large,  irregular  figures. 

The  colors  presented  by  these  patches  are  principally  black, 
white,  and  light  red.  The  black  is  due  to  a  hypertrophy  of  the 
pigmented  epithelial  cells.  The  cells  may  retain  their  normal 
form,  or  may  assume  a  roundish  shape ;  they  may  accumulate  in 
great  numbers,  forming  dark  hillocks;  the  epithelium  surround- 
ing them  is  often  quite  normal,  in  other  cases  poor  in  pigment. 
The  pigment  may  gradually  disappear  from  the  centre  of  these 
dark  hillocks,  so  that  they  present  a  bright  spot  surrounded  by  a 
black  margin.  Lastly,  the  proliferating  epithelial  cells  may  assume 
a  spindle-shaped  form,  and  often  show  a  tendency  to  a  reticulated 
arrangement,  by  which  process  a  delicate  black  net-work  is  formed. 
It  is  noticeable,  moreover,  that  wherever  the  choroidal  epithelium 
bounds  a  sharply  defined  change  of  level  in  the  choroid  it  shows 
a  great  tendency  to  become  blacker.  Accordingly,  both  circum- 
scribed elevations,  such  as  the  irregular  thickenings  of  the  lamina 
vitrea,  and  sharply  defined  depressions,  such  as  small  posterior 
ectasia  in  myopia,  frequently  appear  surrounded  by  a  circle  of 
coal-black  epithelium. 

Within  the  limits  of  the  bright-red  spots  the  choroidal  stroma 
can  sometimes  be  recognized  as  unchanged,  and  sometimes  more  or 
less  atrophied.  These  spots,  therefore,  are  probably  caused  by  a  loss 
of  color  in  the  pigment  epithelium.  The  more  advanced  the  atro- 
phy of  the  choroid,  the  brighter  do  these  spots  become,  so  that 
often  only  a  few  choroidal  vessels  can  be  seen  running  across  the 
white  background  of  the  sclera.  Such  spots,  caused  by  a  circum- 
scribed atrophy  of  the  choroid,  can  generally  be  recognized  as  de- 
pressions in  its  surface,  and  may  either  be  sharply  bounded  by  the 


CHOROIDITIS    DISSEMINATA.  427 

normal  choroid,  or,  at  certain  parts  of  their  circumference,  pass 
over  gradually  into  normal  tissue. 

Such  bright  spots,  whether  caused  by  atrophy  or  by  other 
changes,  are  frequently  surrounded  by  a  border  of  black  pigment, 
or  their  surfaces  present  black,  pigmented,  irregular  figures. 

The  anatomical  changes  which  appear  as  white  spots  in  the 
choroid  are,  however,  the  most  diverse.  They  are  sometimes  due 
to  the  above  described  atrophy  of  the  choroidal  stroma,  sometimes 
to  flat,  bright-colored  layers  of  exudate  upon  the  inner  surface  of 
the  choroid,  sometimes  to  circumscribed  growths  of  cell  elements 
in  the  choroidal  stroma,  and  sometimes  to  fatty  degeneration  of 
the  pigment  epithelial  cells  or  of  the  cells  of  the  stroma. 

Frequently  very  peculiar  changes  of  the  choroidal  epithelium 
occur  in  a  disseminated  form.  For  instance,  in  a  case  of  total 
detachment  of  the  retina,  caused  by  a  sarcomatous  choroidal  tumor 
at  the  equator  of  the  eyeball,  I  found  a  punctated  condition  of  the 
choroid,  which  depended  upon  the  fact  that  the  choroidal  epithe- 
lium, forced  by  an  amorphous  molecular  mass  above  the  plane  of 
the  hyaline  membrane,  formed  numerous  flat  prominences.  Over 
the  entire  extent  of  those  parts  of  the  choroid  thus  changed,  and 
above  the  pigmented  epithelium,  was  a  hyaline,  structureless  mass, 
which  in  many  places  projected  in  irregular  shapes  above  the 
plane  of  the  epithelial  layer,  and,  when  observed  from  its  surface, 
presented  a  peculiar  glistening  appearance. 

The  pathological  processes  to  which  this  disseminated  choroiditis 
is  due  are  only  imperfectly  known,  as  the  opportunity  very  rarely 
occurs  to  examine  such  eyes  anatomically.  As  yet,  only  the  fol- 
lowing anatomical  appearances  have  been  observed: 

There  develop  in  the  choroidal  stroma  disseminated  nodules, 
composed  of  small  non-pigmented  cells  or  nucleated  fibres,  which 
at  a  later  stage  undergo  cicatricial  contraction.  The  surface  of  the 
nodules  is,  at  first,  covered  with  coal-black  epithelium.  '  The  pig- 
mented epithelium  gradually  disappears  from  the  centre  of  these 
black  spots,  leaving  thus  a  bright  spot  surrounded  by  a  black 
border.     The  retina  at  these  places  is  adherent  and  atrophied.* 

At  circumscribed  points    there  occurs  a  proliferation   of  the 

*  Wedl,  Atlas  der  pathol.  Anat.  des  Auges,  Iris  und  Choroidea  v.,  Fig.  54 
und  55 ;  Forster,  Ophthalmol.  Beitrage,  Berlin,  1862,  Choroiditis  areolaris. 


428  CHOROIDITIS    DISSEMINATA. 

pigment  epithelium,  which  penetrates  the  external  and  sometimes 
even  the  internal  granular  layer.  The  new-formed  cells  are  non- 
pigmented.  The  retinal  elements  in  the  affected  places  are  com- 
pletely destroyed,  though  they  may  remain  normal  in  the  immediate 
neighborhood.* 

An  inflammatory  process  in  the  external  layers  of  the  retina 
may  likewise  produce  the  ophthalmoscopic  appearances  of  a  dis- 
seminated choroiditis.f 

The  peripheral  extremities  of  the  radial  fibres  of  the  retina  are 
thickened  and  lengthened,  are  crowded  against  the  inner  surface 
of  the  choroid,  become  bent  upon  themselves,  and  to  some  extent 
adherent  to  each  other.  The  pigment  epithelium  of  the  choroid 
partly  breaks  down,  Avhile  countless  pigment  molecules  or  even 
entire  cells  penetrate  the  substance  of  the  retina. 

Finally,  mention  should  be  made  of  an  anatomical  process 
which  may  furnish  a  similar  ophthalmoscopic  picture,  namely, 
the  thickening  of  the  hyaline  membrane.  Flat  or  hemispherical 
elevations  are  found  upon  it  analogous  to  those  hyaline  growths 
which  occur  upon  the  membrane  of  Descemet,  and  which,  like 
those,  are  most  frequent  as  senile  changes.  But  they  occur  also 
in  young  persons,  and  in  such  cases  generally  in  connection  with 
inflammatory  processes.  The  size  which  they  may  attain,  and 
the  changes  of  the  pigmented  choroidal  epithelium  connected 
with  them,  render  them  visible  to  the  naked  eye,  or  with  the 
help  of  a  lens,  and  accordingly  they  must  be  ophthalmoscopically 
visible.  H.  Miiller;};  has  found  deposits  of  chalk  in  the  eyes  of 
old  people,  partly  in  the  thickened  hyaline  membrane  and  partly 
in  the  tissue  of  the  choroid  itself,  external  to  the  capillary  layer. 
Some  of  these  deposits  have  a  diameter  of  0.5  mm.,  and  accord- 
ingly must  be  ophthalmoscopically  visible. 

It  is  only  seldom  that  the  nature  of  these  diiferent  processes 
and  the  changes  caused  by  them  can  be  determined  by  their  oph- 
thalmoscopic appearances  or  clinical  history.  In  determining 
these  questions  an  examination  of  the  other  parts  of  the  eye  is  of 
the  greatest  importance. 

*  IwanoflF,  Klin.  Monatsbl.,  1869,  pag.  470. 

f  Iiiidnew,  Yirchow's  Arch.,  1869,  B.  xlviii.  pag.  494  ;   Iwanoff,  ].  c. 

X  Arch.  f.  Oi)hth.,  B.  ii.  2,  pag.  1. 


CHOROIDITIS  SYPHILITICA.  .        429 

The  vitreous  generally  remains  clear ;  still,  there  may  be  opaci- 
ties in  it.  The  retina  and  optic  disc  generally  show  no  ophthal- 
moscopic changes.  In  many  cases,  however,  the  participation  of 
the  retina  in  the  pathological  process  is  shown  in  various  ways, 
partly  by  pigmentation  along  the  course  of  the  retinal  vessels, 
partly  by  contraction  of  those  vessels,  especially  of  the  arteries.  A 
change  in  the  optic  nerve  may  proceed  from  the  same  causes.  It 
loses  its  normal  reddish  tinge  as  the  numerous  delicate  vessels  which 
ramify  in  its  intraocular  extremity  become  bloodless.  In  this  con- 
dition it  presents  exactly  the  appearance  of  atrophic  degeneration. 

The  disturbances  of  vision  depend  principally  upon  the  loca- 
tion of  the  disseminated  points  of  inflammation.  They  always 
exercise  a  hurtful  influence  upon  the  retina,  but  so  long  as  only 
a  small  eccentric  part  of  the  visual  field  is  aflected  the  disturb- 
ances are  not  great,  and  accordingly  there  may  be  very  consideral)le 
choroidal  changes  with  relatively  good  vision.  On  the  contrary, 
very  slight  changes  in  the  region  of  the  macula  lutea  injure  direct 
vision  very  seriously.  Although  these  forms  are  so  destructive 
to  the  usefulness  of  the  eye,  they  seldom  lead  to  complete  blind- 
ness, as  eccentric  vision  generally  remains  good  enough  to  enable 
the  patients  to  recognize  their  surroundings. 

Tision  is  affected  in  a  much  higher  degree  in  those  cases  in 
which  the  retina  or  the  optic  nerve  is  essentially  involved  in  the 
pathological  process. 

Choroiditis  syphilitica  is  a  special  clinical  form  which  should 
be  mentioned  in  this  place.  It  is  characterized  by  exceedingly 
small  black,  white,  and  red  spots  scattered  in  the  fundus.  It  is 
always  well  not  to  base  the  diagnosis  upon  the  ophthalmoscopic 
appearances  alone,  but  to  determine  the  existence  of  syphilis  from 
other  symptoms. 

In  choroiditis  disseminata  the  diseased  portions  are  always 
scattered  and  separated  from  one  another  by  normal  tissue.  But 
there  is  another  form  of  choroiditis  which  spreads  uninterruptedly 
over  great  regions  of  the  choroid.  The  posterior  portion  of  the 
choroid  is  generally  the  part  diseased,  while  about  the  periphery 
there  remains  a  border  of  normal  tissue.  Frequently  throughout 
the  entire  fundus,  as  visible  by  the  ophthalmoscope,  no  normal 
region  can  be  seen. 


430  CHOROIDITIS. 

The  epithelium  over  a  great  extent  has  lost  its  color  or  has 
absolutely  broken  down,  and  accordingly  the  stroma  witli  its 
vessels  and  intervascular  spaces  is  very  distinct,  appearing  either 
unchanged  or  more  or  less  atrophied. 

Frequently  there  are  in  the  epithelial  layer,  atrophy,  circum- 
scribed proliferation,  and  pigment  changes  of  the  cells,  and  the 
result  is  a  greater  or  less  number  of  black,  punctated,  or  irregular 
spots,  dark  lines,  and  reticulated  figures.  Frequently  there  are 
accumulations  of  pigment  upon  the  retinal  vessels,  with  contrac- 
tion of  the  larger  vascular  trunks,  and  atrophy  of  the  optic  nerve. 

The  vitreous  may  remain  clear,  but  there  are  more  frequently 
opacities  in  it,  which,  by  their  great  mobility,  show  its  complete 
liquefaction.  This  same  degenerative  process  may  cause  relaxa- 
tion of  the  zonula  and  luxation  of  the  lens. 

As  the  macula  lutea  is  generally  involved,  vision  is  greatly 
interfered  with.     In  many  cases  all  sensation  of  light  is  lost. 

In  the  treatment  of  choroiditis,  especially  of  those  forms  in 
which  the  diagnosis  is  based  simply  upon  the  ophthalmoscopic 
appearances,  the  first  thing  to  be  determined  is  whether  the  in- 
flammatory process  is  still  going  on  or  has  run  its  course.  If 
the  disturbances  of  vision  be  but  recent,  or  if  there  be  signs  of 
an  active  inflammation,  such  as  hypersemia  of  the  ciliary  vessels 
about  the  margin  of  the  cornea,  or  an  abnormal  redness  of  the 
intraocular  extremity  of  the  optic  nerve,  an  antiphlogistic  treat- 
ment is  indicated.  Bleeding  from  the  temple  by  means  of  the 
artificial  leech,  so  much  employed  in  these  cases,  should  be  so 
performed  that  within  a  few  minutes  from  30  to  50  grammes  are 
drawn ;  the  patient  should  then  be  kept  for  at  least  24  hours  in  a 
darkened  room.  If  there  be  no  special  contra-indications,  an  en- 
ergetic mercurial  treatment  should  be  resorted  to,  the  method  by 
inunction  being  employed  in  cases  where  very  threatening  symp- 
toms render  a  rapid  effect  desirable.  If  a  slower  action  be  wished, 
corrosive  sublimate  may  be  employed. 

The  same  treatment  should  be  employed  during  the  inflamma- 
tory exacerbations  in  chronic  cases. 

If  it  be  impossible  to  determine  with  certainty  that  the  inflam- 
matory process  is  yet  going  on,  it  is  still  best  to  try  once  or  twice 
the  efl'ect  of  bleeding ;  but  it  should  not  be  repeated  oftener  if  it 
do  not  appear  to  improve  vision. 


DETACHMENT   OF    THE    CHOROID.  431 

In  suitable  cases  energetic  cathartics,  diaphoretics,  or  iodide  of 
potassium  may  be  employed  instead  of  the  mercurial  treatment. 

According  to  Von  Graefe,*  repeated  puncture  of  the  anterior 
chamber  is  also  beneficial  in  cases  of  chronic  choroiditis  with 
disease  of  the  vitreous. 

In  all  cases,  even  in  those  where  no  special  treatment  is  indi- 
cated, suitable  dietetic  rules  should  be  observed,  and  to  guard 
against  relapses  vision  should  be  spared  as  much  as  possible,  and 
the  eyes  protected  from  all  external  irritation,  from  dazzling  light, 
etc. 

DETACHMENT  OF  THE  CHOROID. 

In  a  few  casesf  the  ophthalmoscope  has  revealed  in  the  fundus 
of  the  eye  a  number  of  circumscribed  prominences,  upon  whose 
surface  the  choroid  as  well  as  the  retina  could  be  seen.  Both 
membranes  had  been  raised  together  from  the  sclera.  The  color 
and  outlines  of  the  ophthalmoscopic  image  are  determined  by  the 
character  of  the  pigment  in  the  individual  cases,  and  also  by  the 
hemorrhages,  which  are  seen  partly  in  the  tissue  of  the  choroid 
and  partly  in  the  retina.  In  a  case  which  I  observed,  the  retina 
itself  upon  the  i^rominences  was  slightly  pigmented. | 

In  many  cases  the  patients  state  that  the  disturbances  of  vision 
connected  with  the  condition  came  on  suddenly.  Generally,  how- 
ever, they  develop  gradually,  and  are  always  very  considerable. 

At  a  later  stage  a  partial  or  total  detachment  of  the  retina 
generally  occurs. 

The  recognition  of  this  condition  ophthalmoscopically  is  a  great 
rarity,  but  a  separation  of  the  choroid  from  the  sclera  is  quite 
frequently  found  on  anatomical  examination.  Von  Ammon,§  for 
instance,  describes  a  case  of  hydrophthalmus,  in  which  the  sclera 
was  separated  from  the  choroid  throughout  the  limits  of  a  cir- 
cumscribed scleral  staphyloma;  a  thin  layer  of  exudate  covered  a 
great  extent  of  the  remaining  portion  of  the  scleral  surface  of  the 
choroid.     In  the  retina  there  were  no  changes  visible  to  the  naked 

*  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  169. 

fV.  Graefe,  Arch.  f.  Ophth.,  B.  iv.  2,  pag.  226;  Liebreich,  Arch.  f. 
Ophth.,  B.  V.  2,  pag.  259;  Liebreich,  Atlas  der  Ophthalmoscopic,  Taf.  vii., 
Fig.  4. 

J  Vorlesungen  iiber  den  Gebrauch  des  Augenspiegels,  pag.  122. 

§  Zeitschrift  f.  Ophthalmologic,  1832,  B.  ii.  pag.  252. 


432  DETACHMENT    OF   THE    CHOROID. 

eye.  In  a  case  of  intraocular  tumor  in  the  region  of  the  ciliary 
body,  Von  Stellwag*  found  a  circumscribed  staphylomatous  up- 
heaval of  the  sclera  from  the  choroid.  In  another  case,  in  which 
there  was  atrophy  of  the  eye  in  consequence  of  irido-choroiditis 
and  detachment  of  the  retina,  the  posterior  part  of  the  choroid 
was  raised  from  the  sclera  by  a  yellow  fluid  mixed  with  pigment 
granules,  and  the  inner  surface  of  this  part  of  the  choroid  was 
cov^ered  with  a  bony  growth. 

Virchowf  found  in  an  eye  which  had  been  destroyed  by  neuro- 
paralytic suppuration  of  the  cornea,  the  choroid  detached  from  the 
sclera  by  an  accumulation  of  thin  purulent  fluid.  There  was 
purulent  infiltration  of  the  choroid,  the  retina,  and  the  vitreous. 

In  a  case  of  purulent  choroiditis  which  I  examined,  the  stroma 
of  the  choroid  was  so  infiltrated  that  at  places  its  inner  surface 
projected  in  hemispherical  nodules  from  3  to  5  mm.  into  the  cavity 
of  the  eyeball.     There  was  total  detachment  of  the  retina.;}: 

In  a  case  in  which  there  were  a  high  degree  of  amblyopia,  lique- 
faction of  the  vitreous,  luxation  and  opacity  of  the  lens,  Knapp§ 
performed  cataract  extraction.  Five  weeks  later  he  enucleated  the 
eye,  because  in  the  ciliary  region  three  brownish,  hemispherical 
prominences  projecting  into  the  vitreous  could  be  seen,  which 
awakened  the  suspicion  of  a  choroidal  melanosarcoma.  The 
anatomical  examination  revealed  an  annular  detachment  of  the 
ciliary  body  and  the  anterior  portion  of  the  choroid  by  a  clear 
fluid.     There  was  no  retinal  detachment. 

In  irido-choroiditis  Iwanofl*]!  has  repeatedly  found  detachment 
of  the  choroid  from  the  sclera.  In  general  such  anatomical  ob- 
servations are  so  frequent  that  it  seems  scarcely  necessary  to  cite 
particular  cases. 

In  the  course  of  acute  or  chronic  choroiditis  exudations  not 
unfrequently  occur  by  which  the  choroid  is  wholly  or  partially 
detached  from  the  sclera.  It  is  possible  that  the  ophthalmoscopic 
picture  of  choroidal  detachment  is  due  to  a  similar  process;  still, 
this  involves  the  assumption  that  copious  and  circumscribed  eifu- 

*  Ophthalmologie,  1856,  B.  ii.  1,  pag.  427  bis  432. 

t  Arch.  f.  Ophth.,  B.  iii.  2,  pag.  430. 

+  Ibid.,  B.  vi.  2,  pag.  265. 

^  Intraoculare  Geschwiilste,  pag.  194  bis  200. 

II  Arch.  f.  Ophth.,  B.  xi.  1,  pag.  191,  und  B.  xv.  2,  pag.  15  bis  46. 


CHOEOIDAL  HEMORRHAGE.  433 

sions  can  take  place  in  the  choroidal  stroma  without  any  apparent 
inflammatory  symptoms,  just  as  is  frequently  the  case  in  detach- 
ment of  the  retina. 

Hemorrhages  in  the  tissue  of  the  choroid  occur  rather  rarely. 
They  appear  as  red  spots,  whose  extent,  form,  and  color  depend 
principally  upon  the  quantity  of  the  effused  blood.  If,  as  is  usual, 
the  hemorrhages  be  not  profuse,  their  ophthalmosco]>ic  appearance 
will  1)6  somewhat  modified  by  the  stroma  pigment  scattered  through 
them,  and  by  the  epithelial  layer  covering  them.  Sometimes  they 
are  sharj)ly  defined,  sometimes  they  lose  themselves  without  any 
distinct  limits  in  the  choroidal  stroma.  Specially  characteristic  is 
the  fact  that  the  retinal  vessels  run  over  them. 

Wounds,  bruises,  or  severe  jars  of  the  eye  are  the  most  frequent 
causes.  Thus,  for  instance,  a  gunshot  wound  which  grazes  the 
wall  of  the  orbit  may  cause  copious  hemorrhage  in  the  tissue  of 
the  choroid  without  any  external  visible  changes  in  the  eye. 

Aside  from  traumatic  causes,  choroidal  hemorrhage  occurs  prin- 
cipally with  acute  choroiditis.  Ophthalmoscopically,  it  is  observed 
frequently  with  high  degrees  of  myopia,  frequently,  too,  in  eyes 
previously  absolutely  healthy,  and  without  any  known  cause. 

The  effect  upon  vision  depends  less  upon  the  effusion  in  the 
choroidal  stroma  than  upon  the  concomitant  changes,  such  as 
retinal  hemorrhages,  opacities,  or  hemorrhages  into  the  vitreous,  etc. 

The  complications,  too,  modify  the  therapeutic  indications. 

Ruptures  of  the  choroid  are  caused  by  external  violence,  such 
as  a  blow,  thrust,  or  shot  wound,  which  either  affects  the  eye  alone 
or  at  the  same  time  fractures  the  bony  walls  of  the  orbit.  The 
rupture  almost  always  occurs  near  the  optic  disc,  and  generally  in 
the  form  of  a  curve,  with  its  concavity  turned  toward  the  disc. 
The  color  within  the  rupture  is  at  first  not  a  clear  white,  but 
somewhat  yellow,  probably  because  the  lamina  fusca  remains  at- 
tached to  the  sclerotic.  Later  the  color  generally  grows  brighter, 
while  the  margins  of  the  rupture  often  grow  dark.  Near  by  are 
generally  small  choroidal  or  retinal  hemorrhages,  which  in  time 
disappear.  There  is  no  apparent  rupture  of  the  retina  or  sclera. 
Frequently  there  is  at  first  traumatic  mydriasis. 

The  result,  as  affects  vision,  depends  upon  the  severity  of  the 


434  TUBERCLE    OF    THE    CHOROID. 

injury.  In  many  cases  there  is  at  the  same  time  considerable 
blood  in  the  anterior  chamber  or  in  the  vitreous,  in  consequence 
of  the  contusion.  In  other  cases  there  develop  in  the  choroid  in- 
flammatory processes,  which  in  the  acute  stage  are  accompanied  by 
opacities  of  the  retina  and  vitreous.  Some  of  the  consequences 
of  the  contusion  are  transitory  and  admit  of  a  complete  recovery 
of  sight ;  generally,  however,  the  disturbances  of  vision  are  very 
great,  and  though  there  may  be  some  improvement  at  first,  it  may 
be  but  temporary,  and  the  condition  may  be  made  still  worse  by 
persisting  choroiditis  or  detachment  of  the  retina,  in  consequence 
of  contraction  of  the  choroidal  cicatrix.* 

The  treatment  of  recent  cases  is  antiphlogistic  in  proportion  to 
the  intensity  of  the  symptoms.  There  is  generally  no  treatment 
which  can  benefit  old  cases. 

Tubercle  of  the  choroid  was  first  demonstrated  anatomically  l)y 
Manz.f  Later,  a  case  was  reported  by  Busch.|  Finally,  Cohn- 
heim§  showed  that  tubercle  of  the  choroid  occurs  almost  constantly 
with  acute  miliary  tuberculosis.  Shortly  afterward  the  subject 
was  discussed  by  Von  Graefe  and  Leber  from  both  a  clinical  and 
an  anatomical  stand-point. || 

Generally  both  eyes  are  affected,  but  such  is  not  always  the 
case.  Frequently  there  is  only  a  single  tubercle  in  the  choroid, 
but  generally  there  are  several,  and  in  some  cases  Cohnheim 
counted  more  than  fifty.  If  only  a  few  tubercles  be  present,  they 
are  always  in  the  neighborhood  of  the  optic  disc  and  macula 
lutea ;  if  their  number  be  great,  they  are  found  even  on  the 
periphery  of  the  choroid.  They  appear  as  uniform  spherical 
nodules,  sometimes  scarcely  visible  to  the  naked  eye,  but  having 
an  average  size  of  from  0.5  to  1  mm.  They  may  even  attain  a 
diameter  of  2.5  mm.  The  smaller  ones  are  covered  by  unchanged 
choroidal  epithelium,  and  therefore  cannot  be  seen  until  after  its 
removal. 

But  in  the  case  of  those  having  a  diameter  of  1  mm.  or  more 


*  Saemisch,  Klin.  Monatsbl.,  18tJG,  pag.  111. 

t  Arch.  f.  Ophih.,  B.  iv.  2,  pag.  120,  und  B.  ix.  3,  pag.  133. 

I  Virchow's  Arch.  f.  path.  Anat.,  B.  xxxvi.  pag.  448. 
§  Ibid.,  B.  xxxix. 

II  Arch.  f.  Ophth.,  B.  xiv.  1,  pag.  183. 


CHOROIDAL   SARCOMA.  435 

the  pigment  is  always  lighter,  and  the  nodule  beneath  it  shimmers 
through,  all  the  more  distinctly  as  the  tubercle  at  this  time  loses 
its  gray  transparent  appearance  in  consequence  of  a  caseous  meta- 
morphosis beginning  at  its  centre.  The  growth  of  the  nodules  is 
always  forward  toward  the  retina,  so  that  they  very  soon  cause 
slight  protuberances  above  the  surface  of  the  fundus.  The  largest 
of  these  appear,  therefore,  as  ])rominent  elevations  with  non-pig- 
mented  surface. 

Ophthalmoscopically,  they  appear  as  bright,  generally  rose- 
tinted  spots,  which  shade  off  without  sharp  boundaries  into  the 
normal  color  of  the  surrounding  fundus.  The  black  pigmented 
border,  so  constant  in  other  similar  choroidal  changes,  is  wanting, 
and  was  observed  by  Cohnheim  in  only  a  single  case,  in  which  the 
tubercle  had  attained  the  unusual  size  of  2.5  mm.  "For  such 
cases  the  well-marked  caseous  degeneration  and  the  distinct  promi- 
nence of  the  nodules  furnish  diagnostic  points.  Simultaneously 
with  tubercle  of  the  choroid  I  have,  several  times  observed  inflam- 
matory changes  in  the  neighboring  parts  of  the  retina. 

Tul)ercle  of  the  choroid  occurs  oftenest  in  connection  with 
acute  miliary  tuberculosis,  and  this  fact  is  of  great  importance 
in  the  diagnosis  of  this  disease.  Exceptionally,  the  choroid  is 
affected  in  forms  other  than  the  acute  miliary  tuberculosis  in 
cases  where  a  great  number  of  different  organs  are  affected.  In 
the  ordinary  chronic  pulmonary,  or  pulmonary  and  intestinal 
tuberculosis,  or  in  general  where  only  a  few  organs  are  affected, 
the  choroid  remains  free. 

Choroidal  tumors  are  all  sarcomatous,  and  with  few  exceptions 
pigmented.  They  are  of  all  degrees  of  consistency,  from  the 
dense  fibrous  forms  to  pap-like,  almost  fluid  masses.  As  yet 
they  have  not  been  observed  during  childhood.  Between  the 
ages  of  15  and  30  years  they  are  rare,  becoming  frequent  only  at 
a  more  advanced  age. 

The  appearances  at  an  early  period  depend,  in  the  first  place, 
upon  the  situation  of  the  tumor.  If  it  be  upon  the  ciliary  body 
or  the  anterior  portion  of  the  choroid,  it  appears  as  a  brownish 
reflecting  prominence,  projecting  into  the  vitreous  behind  the  lens. 
The  possible  error  under  these  circumstances  of  mistaking  it  for 
a  choroidal  detachment  is  avoided  by  observing  that  the  color  is 


436  CHOROIDAL    SARCOMA. 

different  from  that  of  the  normal  choroid,  and  in  very  vascnlar 
sarcomas,  by  the  fact  that  an  irregular  vascular  system  can  be 
recognized  in  the  tumor  itself.  During  its  further  development  the 
tumor  may  dislodge  the  lens  and  become  visible  in  the  periphery 
of  the  anterior  chamber. 

If  the  tumor  develop  deep  in  the  fundus  it  can  seldom  be  seen 
ophthalmoscopically,  for  it  is  generally  hidden  by  an  extensive 
retinal  detachment.  Some  cases,  it  is  true,  have  been  observed 
in  which  the  tumor  developed  in  the  region  of  the  macula  lutea 
or  in  the  upper  or  lateral  portion  of  the  choroid  without  any 
retinal  detachment;  or  the  detachment  remained  circumscribed, 
and  by  its  peculiar  appearance  awakened  the  suspicion  of  its  real 
nature  ;  sometimes  it  was  possible  to  recognize  the  tumor  and  its 
peculiar  vascular  system  through  the  detached  retina.*  But  such 
cases  are  exceptions.  In  the  great  majorit_y  of  cases  there  occurs 
an  early  detachment  of  the  retina. 

The  diagnosis  is  generally  not  possible  until  either  the  growing 
tumor  again  reaches  the  posterior  surface  of  the  retina  and  becomes 
visible  through  it,  or  till  glaucomatous  symptoms  appear.  The 
tension  of  the  eye  increases,  the  pupil  is  dilated  and  rigid,  the 
cornea  anaesthetic,  the  anterior  chamber  shallow,  the  subconjunc- 
tival veins  dilated,  and  scleral  staphyloma  and  optic-nerve  ex- 
cavation developed.  In  many  cases  glaucomatous  inflammation 
appears.  At  last  cataract  comes  on,  and  the  appearance  as  of 
glaucomatous  blinding  is  then  so  decided  that  even  in  this  stage 
the  diagnosis  would  be  impossible  if  the  course  of  the  disease  had 
not  been  observed  from  the  beginning. 

Sooner  or  later  the  tumor  grows  beyond  the  limits  of  the 
eyeball,  and,  according  to  circumstances,  in  one  of  three  different 
ways.  Often  at  an  early  period  it  creeps  along  the  oj^tic  nerve. 
Black  pigment  is  infiltrated  into  the  perineurium  posterior  to  the 
lauiina  cribrosa.  Its  quantity  increases,  and  it  gradually  extends 
backward  between  the  nerve  fibres,  distending  the  nerve  and 
propagating  the  disease  into  the  orbit  or  even  into  the  cranial 
cavity. 

Or  an  actual  perforation  occurs,  generally  through  the  margin 
of  the  cornea,  sometimes  through  the  sclerotic.     The  dark  mass 

*  Becker,  Arch.  f.  Augen-  unci  Ohrenheilk.,  B.  i.  2,  pag.  214. 


COLOBOMA    OF   THE   CHOROID.  437 

presses  forward  through  the  opening  and  spreads  out  as  a  black 
fungoid  growth,  inclined  to  hemorrhage  and  ulceration. 

Or  finally,  black  nodules  appear  on  the  outer  surface  of  the 
sclerotic,  seldom  in  distinct  connection  with  the  intraocular  tumor, 
but  apparently  independent  growths.  Microscopic  examination, 
however,  generally  shows  that  there  is  a  progressive  disease  of  the 
sclerotic  elements.  When  these  nodules  have  once  appeared,  the 
increase  of  the  tumor  within  the  orbit  goes  on  very  rapidly: 

This  course  is  only  occasionally  varied  by  the  occurrence  of 
corneal  ulceration  with  consecutive  atrophy  of  the  eye  before  the 
ball  has  become  completely  filled  with  the  tumor. 

The  presence  of  this  form  of  atrophy  may  embarrass  the  diag- 
nosis. The  signs  of  an  intraocular  tumor  are  severe  spontaneous 
paroxysms  of  pain  and  a  peculiar  form  of  the  atrophied  eye.  It 
is  not,  as  under  ordinary  circumstances,  contracted  in  a  quite  uni- 
form concentric  manner,  but  more  in  a  direction  from  before  back- 
ward, as  the  atrophy  begins  at  a  time  when  the  posterior  portion 
of  the  ball  is  already  filled  by  the  tumor.  In  these  cases,  as  a 
rule,  there  is  generally  at  last  a  growth  of  the  tumor  into  the 
orbit,  and  the  atrophied  eye  appears,  therefore,  less  sunken  than 
in  ordinary  cases  of  atrophy. 

As  soon  as  the  diagnosis  of  choroidal  sarcoma  is  made,  or 
when,  in  the  case  of  an  already  blinded  eye,  it  can  be  assumed  as 
highly  probable,  the  enucleation  of  the  eye  is  indicated.  If  there 
be  a  morbid  growth  in  the  orbit,  the  method  by  periosteal  extirpa- 
tion is  preferable  (see  page  200).  It  is  always  a  matter  of  doubt 
up  to  iiow  late  a  time  the  operation  will  be  useful  in  prolonging 
the  patient's  life,  for  at  any  stage  of  its  development  the  cho- 
roidal sarcoma  may  be  complicated  by  deposits  in  the  liver,  in 
the  nervous  centres,  etc.  Respecting  the  relation  of  these  de- 
posits to  the  primary  tumor,  it  cannot  be  determined  upon  existing 
data  whether  they  actually  depend  upon  it  or  are  simply  due  to  a 
common  cause  (dyscrasia).* 

Coloboma  of  the  choroid  occurs  in  connection  with  congenital 

coloboma  iridis.    It  is  very  rare  without  this  defect  of  development. 

The  defect  is  always  in  the  lower  portion  of  the  choroid,  and 

*  Von  Giaefe,  Arch.  f.  Opbth.,  E.  xiv.  2,  pag.  103. 


438  COLOBOMA    OF   THE    CHOROID. 

may  begin  at  the  optic  disc,  or  somewhat  above  it,  and  extend  so 
far  downward  that  its  anterior  limit,  that  turned  toward  the  iris, 
cannot  l)e  seen  by  ophthahnoscopic  examination.  As  a  rule,  how- 
ever, the  anterior  limit  is  so  far  behind  the  ora  serrata  that  it  is 
distinctly  visible.  The  place  of  the  choroidal  defect  appears 
white,  because  here  the  sclera,  being  covered  only  by  transparent 
retinal  tissue  and  slight  traces  of  the  choroid,  is  exposed  to  the 
ophthalmoscopic  illumination.  In  some  cases  remnants  of  pig- 
mented tissue  are  strewed  upon  the  white  surface.  More  fre- 
quently there  is  no  trace  of  choroidal  tissue.  The  vessels  branching 
upon  the  bright  surface  of  the  choroid,  and  the  shadows  visible 
upon  it,  prove  that  the  surface  of  this  portion  of  the  sclera  is  ir- 
regularly undulating.  The  margins  of  the  ectasia  are  generally 
characterized  by  a  very  dark  pigmentation  of  the  choroid.  In 
other  cases  this  pigmentation  occurs  only  at  places  about  the 
margin,  or  it  forms  a  very  slight  line  about  the  defect. 

The  optic  disc  may  be  normal,  or  be  more  or  less  changed. 
For  instance,  it  may  present  irregular  depressions,  or  an  unusual 
shape,  in  consequence  of  a  distortion  of  the  optic-nerve  sheath. 
If  the  optic  disc  be  surrounded  by  the  coloboma,  it  may  be  either 
normal  and  distinctly  defined,  or  it  may  be  irregular  in  shape 
and  shade  off  imperceptibly  into  the  surrounding  sclera. 

Not  infrequently  the  retinal  vessels  spring  in  an  irregular  man- 
ner from  the  nerve.  In  cases  where  they  reach  the  coloboma,  and 
where  the  coloboma  itself  does  not  extend  to  the  disc,  the  retinal 
vessels  may  either  pass  around  the  defect,  coursing  along  its  border, 
or  they  or  their  branches  may  pass  into  the  defect.  In  many  cases 
the  parallax  shows  that  the  retina,  with  its  vessels,  is  stretched 
like  a  bridge  over  the  scleral  ectasia.  In  other  cases  the  retina 
follows  all  the  changes  of  level  in  the  coloboma.  Besides  the 
retinal  vessels,  there  can  often  be  seen  within  the  defect  a  number 
of  sinuous  vessels  belonging  to  the  clioroid,  the  trunks  of  some 
of  them  penetrating  the  sclera. 

Coloboma  of  the  choroid  occurs  both  bilaterally  and  unilaterally, 
and  in  the  latter  case  generally  on  the  left  side.  Frequently  the 
eye  aftected  is  somewhat  smaller  than  normal ;  often  there  is 
decided  microphthalmus.  Central  vision  may  be  normal,  or  more 
or  less  affected.  Eccentric  vision  generally  shows  a  defect  corre- 
sponding to  the  position  of  the  coloboma. 


DISEASES  OF  THE  RETINA  AND  OF  THE  OPTIC  NERVE. 


A  EAEE  anomaly  of  the  retina,  which  probably  should  hardly 
be  regarded  as  a  pathological  condition,  is  that  in  which  there 
is  persistence  of  the  medullary  sheaths  of  the  nerve  fibres.  The 
0])hthalmoscopic  picture  in  such  cases  is  very  striking. 

A  bright  white  spot  is  seen,  generally  close  about  the  margin  of 
the  optic  disc,  and  in  rare  cases  extending  upon  it.  Otherwise 
the  retina  is  normal,  and  vision  is  jjerfect.  The  spot  sends  out 
radiating  stripes  from  its  periphery.  A  similarly  arranged  stria- 
tion  can  be  detected  upon  the  surface  of  the  spot  when  examined 
in  the  upright  image.  Sometimes  this  portion  is  slightly  elevated 
above  the  general  surface  of  the  retina.  This  spot  completely 
hides  the  choroid,  showing  that  the  changes  are  in  the  retina; 
while  the  fact  that  it  veils  or  completely  hides  the  retinal  vessels 
at  places,  shows  that  the  changes  must  be  in  the  nerve-fibre  layer. 

As  a  rule,  these  changes  occupy  only  a  portion  of  the  median, 
upper,  or  under  margin  of  the  optic  disc,  extending  upon  the 
retina  about  one  diameter  of  the  disc.  Frequently  their  extent 
is  smaller,  and  only  seldom  is  it  much  larger,  and  when  such  is 
the  case  the  white  fibres,  as  they  spread  out  in  the  periphery, 
avoid  the  macula  lutea  by  curving  about  it. 

This  ophthalmoscopic  appearance  is  very  similar  to  that  seen 
to  the  right  and  left  of  the  optic  disc  in  the  rabbit's  eye,  and 
which  there  can  be  demonstrated  to  be  due  to  the  persistence  of 
the  myelin  sheaths  upon  the  fibres  of  the  retina. 

Furthermore,  Virchow,*  Beckmann,t  and  Von  Reckling- 
hausen|  have  observed  white  spots  in  the  retina,  which,  upon 
microscopic  examination,  proved  to  be  caused  by  the  myelin 
sheaths  with  which  the  fibres  are  covered  at  these  places.     Vir- 


*  Arch.  f.  path.  Anat.,  B.  s.  pag.  190. 
f  Ibid.,  B.  xiii.  pag.  97. 
X  Ibid.,  B.  XXX.  pag.  375. 

439 


440  MEDULLARY    FIBRES    OF    RETINA. 

chow  at  the  same  time  found  in  these  cases  that  the  optic-nerve 
fibres  lost  their  myelin  sheaths  in  the  ordinary  manner  at  the 
lamina  cribrosa,  but  that  after  a  short  interval,  through  which 
the  nerve  runs  as  a  simple  axis  cylinder,  the  sheath  reappears, 
and  finally  is  again  lost.  This  reappearance  of  the  myelin  sheath 
may  occur  at  some  distance  from  the  optic  disc ;  for  instance,  in 
Von  Recklinghausen's  case  it  was  4  ram.  from  its  margin.  This 
condition  is  of  course  more  frequently  observed  by  ophthalmo- 
scopic than  by  anatomical  examination. 

In  the  case  of  a  post-mortem  examination  made  in  the  Berlin 
Charity  Hospital  of  a  subject  who  during  life  had  presented  the 
above  described  ophthalmoscopic  appearance,  Prof.  Virchow  had 
the  kindness  to  examine  the  preparation,  and  demonstrated  ana- 
tomically the  persistence  of  the  medullary  sheaths.  H.  Schmidt* 
also  reports  a  case  in  which  the  ophthalmoscopic  diagnosis  was 
confirmed  by  post-mortem  examination. 

The  capacity  of  the  fibres  to  conduct  impressions  appears  to  be 
in  no  way  affected.  But  the  consequence  of  their  opacity  is  a 
circumscribed  defect  in  the  visual  field  corresponding  to  the  posi- 
tion of  the  white  spot  seen  by  the  ophthalmoscope.  It  is  gener- 
ally continuous  with  Mariotte's  blind  spot,  and,  like  that,  is  not 
subjectively  perceived  as  a  defect  in  the  visual  field. 

In  connection  with  this  anomaly,  especially  when  of  a  high 
degree,  there  is  often  very  poor  vision,  which,  however,  according 
to  Mauthner,t  appears  to  depend  rather  upon  co-existing  hyper- 
metropia  with  amblyopia  congenita. 

This  anomaly  occurs  upon  one  or  both  sides.  Most  probably 
it  is  congenital. 

Hyperremia  of  the  retina  is  characterized  by  a  reddening  of  the 
intraocular  extremity  of  the  optic  nerve  and  a  dilatation  and  sin- 
uosity of  the  retinal  veins.  It  occurs  as  a  collateral  fluxion  in 
connection  with  inflammation  of  other  parts  of  the  eye,  or  as  one 
of  the  symptoms  of  retinitis,  or  as  a  venous  obstruction  of  the 
retinal  veins,  caused  by  compression  at  some  part  of  their  course, 
or  as  a  part  of  an  extensive  venous  stagnation,  as,  for  instance,  is 
often  seen  in  cyanosis  congenita. 


*  Klin.  Monat.sbl.  f.  Augenheilk.,  1874,  pag.  186. 
f  Lehrbuch  der  Ophthalmoscopic,  pag.  266. 


1 


DETACHMENT   OF    THE    RETINA.  441 

Hyperfeniia  of  the  retina,  accordingly,  is  not  to  be  regarded 
clinically  as  an  independent  form  of  disease. 

DETACHMENT   OF   THE    RETINA. 

Detachment  of  the  retina  from  the  choroid  by  an  effusion  of 
fluid  between  the  two  membranes  causes  two  changes  of  great  im- 
portance in  the  diagnosis.  The  detached  retina  is  brought  nearer 
the  middle  point  of  the  eye,  and  it  becomes  wrinkled.  Even  in 
very  myopic  eyes  the  detached  retina  generally  lies  in  front  of 
the  principal  focus  of  the  dioptric  apparatus.  It  can  therefore  be 
seen  very  easily  in  the  upright  image.  It  is  wrinkled  because 
the  spherically  stretched  membrane,  when  forced  toward  the  centre 
of  the  eyeball,  presents  a  smaller  superficies. 

Frequently  the  detached  portion  is  so  relaxed  that  the  move- 
ments of  the  eye  impart  to  it  wave-like  undulations.  This  float- 
ing of  the  detached  retina  is  a  very  characteristic  and  important 
diagnostic  symptom,  but  it  is  not  always  present.  The  condition 
upon  which  it  depends  is  the  presence  both  before  and  behind  the 
detached  retina  of  a  thin  fluid, — that  is,  there  must  be  either  a 
liquefaction  or  a  detachment  of  the  vitreous  with  a  serous  effiision 
between  it  and  the  retina. 

The  detached  retina  is  recognized  in  the  same  manner  as  under 
normal  conditions, — by  its  vessels  and  by  the  appearance  of  the 
membrane  itself. 

The  appearance  of  the  vessels  is  very  characteristic.  They 
follow  all  the  wrinkles  and  folds  of  the  detached  portion ;  their 
course,  therefore,  is  exceedingly  irregular,  and  certain  portions  of 
the  vessels  which  lie  in  the  depths  of  the  folds  are  invisible. 

The  boundary-line  between  the  normal  and  the  detached  portion 
of  the  retina  can  generally  be  recognized  by  the  change  of  direction 
which  the  retinal  vessels  experience  in  crossing  it.  Often  the 
distinction  in  color  between  the  two  portions  is  very  marked. 

The  detached  retina  in  most  cases  is  of  a  bright-gray  color,  in- 
terspersed at  places  with  a  brownish-green  or  yellow  tinge,  and  its 
vessels  seen  against  the  lighter  colored  background  appear  darker 
than  normal. 

This  difference  in  color  depends  on  sev^eral  causes.  The  tension 
of  the  detached  portion  is  diminished,  and  this  diminishes  its 
transparency.     It  seems  more  opaque  than  normal,  for  the  reason 

29 


442  bETACHMENT   OF  THE   EETINA. 

that  we  do  not  view  it  in  a  direction  perpendicular  to  its  surface, 
but,  on  account  of  its  detachment  and  foldings,  always  under 
an  angle.  Still  further,  there  are  those  secondary  inflammatory 
changes  which  generally  develop  in  consequence  of  detachment. 
The  layer  of  the  rods  and  cones  is  the  first  to  suffer;  its  elements 
swell  and  break  down  under  the  action  of  the  subretinal  fluid. 
Somewhat  later,  inflammatory  processes  begin,  especially  in  the 
outer  layers.  Proliferation  of  the  connective-tissue  elements  is 
set  up,  and  finally,  after  total  detachment  has  existed  for  some 
time,  the  retina  loses  all  its  specific  elements  and  is  transformed 
into  a  funnel-shaped  fibrous  membrane,  its  posterior  end  attached 
at  the  optic  nerve  and  its  anterior  end  at  the  ora  serrata,  en- 
closino;  the  residuum  of  the  vitreous,  which  has  likewise  under- 
gone  a  fibrous  degeneration.  At  this  advanced  stage  the  opacity 
of  the  lens  and  the  irido-choroiditis  render  the  ophthalmoscopic 
examination  ho  longer  possible. 

The  character  of  the  fluid  behind  the  detached  retina  has  also 
an  influence  upon  its  color.  It  has  generally  a  different  refractive 
power,  another  color,  and  less  transparency  than  the  vitreous.  It 
is  generally  very  coagulable  by  heat,  and  contains  some  blood-cor- 
puscles and  nucleated  cells  of  various  sizes;  cholesterin  crystals 
are  also  sometimes  found  in  it.  It  may  be  the  presence  of  these 
crystals  which,  in  rare  cases,  causes  the  detached  retina  to  appear 
as  if  strewed  with  a  great  number  of  small,  bright  specks,  whose 
reflexes  change  according  to  the  position  of  the  mirror. 

The  retinal  detachment  is  generally  betrayed  by  the  absence  of 
the  normal  red  color  of  the  pupil,  when  illuminated  by  the  ophthal- 
moscope. 

Recent  detachments,  and  sometimes  older  ones,  are  more  difficult 
to  recognize,  for  the  reason  that  the  retina  and  the  fluid  behind  it 
remain  unusually  transparent.  Still,  in  such  cases  the  diagnosis 
may  be  made  certain  by  the  irregularity  in  the  course  of  the  ves- 
sels, and  by  the  reflex  from  the  retina  itself.  This  reflex  is  most 
distinct  in  the  folds  of  the  membrane,  but  can  also  be  plainly 
seen  in  the  examination  in  the  upright  image,  if  the  retina  be 
brightly  illuminated  and  slight  movements  of  the  mirror  be  made, 
by  which  the  inverted  image  of  the  flame  is  caused  to  pass  over  the 
detachment.  One  may  thus  satisfy  himself  that  it  lies  far  in  front 
of  the  choroid. 


DETACHMENT   OF   THE   EETIXA.  443 

Frequently  the  retina  is  detached  only  in  the  form  of  a  few 
small  folds,  which  may  be  recognized  by  their  brighter  color,  but 
more  surely  by  the  behavior  of  the  retinal  vessels  running  over 
them. 

In  the  great  majority  of  cases  the  detachment  is  at  the  lower 
part  of  the  retina,  for  the  fluid,  even  if  the  detachment  began 
above,  naturally  sinks  downward.  The  upper  part,  originally 
detached,  may  under  such  circumstances  sink  back  into  its  normal 
position,  and  even  resume  its  function. 

In  recent,  extensive  detachments  the  retina  is  frequently  seen  to 
be  torn.  The  rent  presents  sharp  edges,  somewhat  rolled  away 
from  each  other,  so  that  the  choroid  can  be  seen  between  them 
with  great  distinctness.  In  old  detachments  these  rents  are  less 
frequent,  which  may  be  explained  by  the  sinking  of  the  subretinal 
fluid.  At  least,  I  have  satisfied  myself  that  rents  in  the  upper 
portion  of  the  retina,  which  at  first  were  very  distinct,  could  no 
longer  be  seen  after  the  lower  part  had  become  detached  by  the 
sinking  of  the  fluid,  and  the  upper  part  had  settled  back  into  its 
normal  position. 

The  disturbances  of  vision  are  due  to  the  fact  that  the  abnormal 
position  and  the  folds  in  the  retina  prevent  the  formation  of  any 
distinct  images  upon  it.  The  subjective  sensation  caused  by  this 
condition  is  that  of  a  cloud  in  the  field  of  vision.  In  recent  cases 
the  detached  retina  is  often  still  sensitive  to  light.  At  the  margin 
of  the  visual  field  the  patient  can  often  count  fingers.  This  is 
sometimes  the  case  even  in  old  detachments,  at  least  by  bright 
illumination.  When  the  above  described  inflammatory  changes 
appear,  sensitiveness  to  light  is  generally  entirely  lost. 

Central  vision,  too,  appears  to  suifer  from  the  very  first,  perhaps 
for  the  reason  that  by  the  detachment  of  a  portion  of  the  retina 
the  remaining  part  loses  its  normal  tension. 

As  the  margin  of  the  detachment  approaches  the  macula  lutea, 
metamorphopsia  occurs,  so  that  objects  appear  slanting  and  crooked. 
Even  a  detached  macula  lutea,  if  it  be  not  wrinkled,  may  retain 
some  degree  of  vision,  so  that  large  letters  (No.  12  to  14  Jaeger) 
can  be  read.  When  the  perception  of  light  is  lost  at  this  place, 
the. result  is  eccentric  fixation,  a  neighboring  portion  of  the  retina 
being  used  for  this  purpose,  and  generally  the  axis  of  vision 
deviates  upward. 


444  DETACHMENT   OF   THE   RETINA. 

Opacity  of  the  vitreous  very  often  exists  at  the  same  time  with 
detachment  of  the  retina. 

The  disturbances  of  vision  generally  come  on  suddenly,  and 
increase  rapidly  in  degree.  In  recent  cases  the  time  of  the  begin- 
ning of  the  trouble  can  generally  be  accurately  determined,  and 
still  it  is  seldom  possible  to  trace  it  back  to  any  particular  cause. 
The  patients  most  frequently  refer  it  to  colds  or  to  straining  the 
eyes.  I  have  repeatedly  been  able  to  satisfy  myself  that  there 
may  for  years  be  small  retinal  detachments  in  the  peripheral  part 
of  the  fundus  without  the  patient  being  aware  of  their  existence. 

Retinal  detachments  may  occur  in  eyes  hitherto  sound,  as  well 
as  in  those  which  have  been  diseased.  Retinitis  haemorrhagica, 
syphilitica,  or  that  of  Bright's  disease  seldom  causes  it.  Choroid- 
itis is  a  more  frequent  cause.  It  almost  always  occurs  with  acute 
irido-choroiditis,  though  it  may  not  be  a  prominent  symptom  in 
these  Ciises.  Chronic  choroiditis  generally  leads  either  to  abnor- 
mal adhesions  between  the  retina  and  the  choroid  or  to  detachment 
of  the  retina.  In  rare  cases  both  these  processes  take  place  at 
different  portions  of  the  fundus. 

Detachment  of  the  retina  most  frequently  occurs  in  connection 
with  a  high  degree  of  myopia.  This  is  true  in  so  great  a  majority 
of  cases  tliat  there  must  be  some  causative  relation  between  the 
two  conditions.  It  has  been  usual  to  explain  this  connection  on 
purely  mechanical  grounds.  It  is  said  that  during  the  progressive 
distention  of  the  sclera  the  choroid  yields  with  it.  But  the  retina 
being  only  loosely  attached  to  the  choroid,  shows  a  tendency  to 
become  detached  rather  than  to  suifer  a  distention  corresponding 
with  that  of  the  other  membranes.  It  is  plain  that  this  view  is 
based  upon  an  error.  It  could  apply  only  to  a  distention  of  the 
sclera  by  a  force  acting  from  without,  since  it  is  impossible  for  a 
pressure  acting  first  upon  the  inner  surface  of  the  retina  to  cause 
its  detachment.  Perhaps  at  present  no  better  explanation  can  be 
given  than  that  myopic  eyes  in  general  are  especially  predisposed 
to  intraocular  diseases. 

Opacities  of  the  vitreous  precede,  accompany,  or  follow  detach- 
ment of  the  retina.  There  must  necessarily  be  a  disturbance  in 
the  nutrition  of  the  vitreous,  for  its  volume  is  reduced  with  the 
same  rapidity  and  in  the  same  proportion  as  the  effusion  accumu- 
lates behind  the  retina.     I  have  been  able  to  confirm  by  anatom- 


DETACHMENT    OF   THE   RETINA.  445 

ical*  examination  the  assertion  made  by  H.  Muller,t  that  in  a 
class  of  cases  detachment  of  the  retina  is  caused  by  shrinking  of 
the  vitreous ;  but  such  cases  appear  to  be  rather  rare  exceptions. 
Clinical  experience  forces  us  to  this  conclusion.  The  freely  mova- 
ble opacities  of  the  vitreous,  which  are  so  frequent,  when  they 
shrink,  of  course  cannot  cause  detachment  of  the  retina.  Only 
such  stringy  opacities,  fastened  at  both  ends,  as  those  existing  in  a 
case  Avhich  I  reported,  can  exercise  traction  on  the  retina,  while 
contraction  of  the  vitreous  as  a  whole  appears  rather  to  cause  an 
effusion  between  it  and  the  retina. 

Von  Graefe  has  called  attention  to  the  fact  that  the  contraction 
following  perforating  wounds  of  the  sclera  may  lead  to  detach- 
ment of  the  retina.  Saemisch  refers  choroidal  ruptures  to  the  same 
cause. 

In  many  cases  detachment  of  the  retina  occurs  as  the  immediate 
consequence  of  a  contusion  of  the  eye.  Often  in  such  cases  a 
hemorrhage  may  have  taken  place  between  the  retina  and  the 
choroid.  In  other  cases,  even  very  shortly  after  the  injury,  the 
fluid  shows  no  bloody  color. 

Among  the  rarer  causes  are  inflammation  of  the  orbital  tissue,^ 
intraocular  cysticercus,  and  choroidal  and  retinal  tumors. 

According  to  Iwanoff,§  detachment  of  the  retina  may  be  caused 
by  that  peculiar  condition  which  he  describes  as  oedema  of  the 
retina.  A  peculiar  change  is  generally  found  in  the  peripheral 
portion  of  the  retina  in  the  eyes  of  old  persons,  visible  to  the 
naked  eye  upon  anatomical  examination.  In  a  meridional  section, 
at  a  distance  of  from  0.5  to  2.0  mm.  from  the  ora  serrata,  the 
thickness  of  the  retina  suddenly  increases,  and  again  as  suddenly 
decreases  at  the  ora  serrata.  The  corresponding  zone  of  the  retina, 
seen  from  the  surface,  appears  traversed  by  zigzag  stripes.  These 
bright  stripes  are  conduits  filled  with  a  homogeneous,  transparent, 
probably  fluid  substance;  they  run  between  fibrous  bundles  placed 
at  right  angles  to  the  surface  of  the  retina.  The  fibres  consti- 
tuting these  bundles  radiate  at  both  extremities  in  the  plane  of 


*  Arch.  f.  Ophth.,  B.ix.  1,  pag.  199.  f  Ibid.,  B.  iv.  1,  pag.  372. 

+  Von  Graefe,  Klin.  Monatsbl.,  1863,  pag.  49;  Berlin,  ibid.,  1866,  pag.  77  ; 
Becker  und  Kydel,  Wiener  med.  Wochenschrift,  1866,  No.  65. 
I  Arch.  f.  Ophth.,  B.  xv.  2,  pag,  88. 


446  DETACHMENT   OF   THE   RETINA. 

the  surface  of  the  retina.  Upon  a  section  made  perpendicularly 
through  the  retina  these  conduits  present  a  series  of  openings, 
either  circular  or  elliptical  in  shape,  their  longest  diameter  being 
at  rio;ht  ang-les  to  the  surfaces  of  the  retina.  The  averasre  diam- 
eter  of  these  openings  is  0.13  mm.  If  the  section  be  thick  enough, 
a  second  series  of  bundles  and  openings  can  be  seen  below  the 
first.  The  bundles  contain  blood-vessels,  and  are  composed  of 
nucleated  fibres.  Enclosed  in  the  openings  nearest  the  ora  ser- 
rata  are  a  greater  or  less  number  of  cystoid  corpuscles.* 

According  to  Iwanoff,  this  condition  obtains  not  exclusively  in 
old  age,  but  also  as  an  undoubted  pathological  process  in  young 
persons,  and  that,  too,  quite  frequently.  Tiie  changes  may  extend 
from  the  ora  serrata  7  or  8  mm.  toward  the  equator,  or  may  occur 
isolated  in  any  part  of  the  retina. 

The  cysts  may  attain  such  a  size  that  they  can  be  seen  with 
the  naked  eye.  Merkelf  states  that  their  inner  walls  consist  of  a 
membrane  lined  with  cells.  The  height  of  the  cysts  is,  as  a  rule, 
from  2  to  6  mm.,  their  diameter  from  4  to  8  mm.  In  one  case 
Iwanoff  saw  a  cyst  which  occupied  one-half  the  retina  and  filled 
two-thirds  of  the  eye.  In  fact,  as  I  have  already  stated,!  the 
ophthalmoscopic  examination  not  infrequently  reveals  circum- 
scribed detachments  of  the  retina  protruding  like  a  tense  cyst 
into  the  vitreous  space. 

When  detachment  of  the  retina  has  once  begun,  its  course  is 
generally  unfavorable,  and  it  may  be  regarded  as  very  fortunate 
if  only  the  status  quo  be  preserved.  At  a  later  stage  iritis  is  very 
likely  to  come  on,  and  under  these  circumstances  is  particularly 
liable  to  be  associated  with  choroiditis.  With  this  condition  of 
affairs  the  lens  always  becomes  opaque ;  but,  on  the  other  hand, 
the  process  may  be  reversed ;  the  opacity  of  the  lens  may  develop 
first,  and  its  swelling  and  pressure  upon  the  iris  be  the  exciting 
cause  for  an  acute  iritis. 

In  reference  to  prognosis,  it  is  to  be  remembered  that  the  con- 
ditions which  favor  a  detachment  of  the  retina,  such,  for  instance, 


*  Comp.  Henle,  Anatomie,  B.  ii.  pag.  670. 

•j-  Ueber  die  macula  lutea  des  Menschen  und  die  ora  serrata  einiger  Sauge- 
tbiere,  Leipzig,  1870. 

X  Vorlesungen  iiber  den  Gebrauch  des  Augenspiegels,  Berlin,  1863,  pag.  121, 


PIGMENTATION   OF   THE    RETINA.  447 

as  a  high  degree  of  myopia,  frequently  exist  simultaneously  in 
both  eyes,  and  that  consequently  there  is  great  danger  of  complete 
blindness.  Bilateral  detachment  of  the  retina  seldom  occurs  unless 
with  myopia;  still,  it  has  been  observed. 

Spontaneous  recovery  with  the  reposition  and  resumption  of 
function  on  the  part  of  the  detached  retina  sometimes  occurs,  but 
only  as  a  rare  exception.  The  usual  treatment  by  cathartics  has 
proved  to  be  of  but  little  benefit. 

Von  Graefe  and  Bowman  undertook  to  introduce  the  practice 
of  incising  the  detached  retina.  Von  Graefe  used  two  broad 
needles  and  Bowman  two  fiiie  needles,  in  the  same  way  as  for  the 
discision  of  secondary  cataract.  In  some  few  cases  the  operation 
has  proved  useful,  but  generally  only  a  slight  and  temporary 
improvement 'is  obtained.  Bad  consequences,  too,  have  been  seen 
to  follow  the  operation.  Upon  the  whole,  the  practi<;e  cannot 
be  recommended  ;  for  the  cases  of  spontaneous  rupture  of  the 
retina,  in  which  there  is  a  larger  perforation  than  can  be  obtained 
by  an  operation,  are  seldom  followed  by  the  reposition  of  the 
membrane.  Moreover,  no  statistics  have  ever  been  presente<l  to 
prove  the  oft-repeated  assertion,  that  those  cases  in  which  spon- 
taneous rupture  of  the  retina  occurs,  run  a  more  favorable  course 
than  others. 

PIGMENTATION   OF   THE    RETINA- 

The  subjective  symptoms  of  the  pigment  degeneration  of  the 
retina  are  so  characteristic  that  in  most  cases  the  ophthalmoscopic 
appearances  can  be  predicted  from  them. 

Hemeralo})ia  is  generally  the  first  symptom  of  the  disease. 
During  daylight  vision  is  sufficiently  good,  but  toward  evening, 
and  at  night,  it  is  so  poor  that  even  large  objects  can  no  longer  be 
recognized,  and  the  patients  generally  cannot  move  about  alone. 

The  investigations  made  by  Maes,*  under  Donders'  supervision, 
have  demonstrated  that  the  hemeralopia  is  simply  due  to  a  con- 
dition which  he  very  appropriately  described  as  torpor  retinee. 
The  retina  reacts  only  under  the  stimulus  of  a  strong  light,  and 
very  slightly,  or  not  at  all,  under  a  weak  illumination.  The 
symptoms  of  hemeralopia  may  be  produced  at  any  time  by  bring- 

*  Over  torpor  retinae,  Utrecht,  1861. 


448  PIGMENTATION   OF   THE    RETINA. 

ing  the  patient  into  a  closed  room  wliere  the  artificial  illumina- 
tion can  be  regulated  at  will.  The  influence  of  the  intensity  of 
the  lighty  upon  both  direct  and  indirect  vision,  can  thus  be  easily 
shown.  It  is  generally  most  evident  as  affecting  indirect  vision. 
The  field  of  vision  is  contracted,  its  boundary-line  being  very 
irregularly  traced  around  the  fixation-point.  As  a  rule,  central 
vision  is  also  affected,  and  in  cases  in  which,  by  full  daylight, 
vision  is  still  nearly  normal,  it  diminishes  with  disproportionate 
rapidity  as  the  illumination  grows  fainter. 

Gradually,  as  the  process  goes  on,  the  visual  field  contracts,  so 
that  defects  appear  on  its  periphery  even  by  bright  illumination. 
Central  vision  also  soon  begins  to  suffer,  and  absolute  blindness 
comes  on. 

Ophthalmoscopic  examination  reveals  a  pigmentation  of  the 
retina,  beginning  at  the  periphery,  and  extending  inward  toward 
the  macula  lutea.  The  pigment  is  of  a  deep-black  color,  in  the 
form  of  irregular,  radiating  specks,  much  resembling  highly  mag- 
nified bone-corpuscles.  The  location  of  the  pigment  in  the  retina 
is  made  evident  by  an  unmistakable  relation  which  it  presents  to 
the  retinal  vessels,  whose  walls,  at  places,  are  accompanied  by 
pigment  stripes. 

At  first  the  pigmentation  is  very  sparse,  and  to  be  found  only 
by  a  careful  examination  of  the  periphery  of  the  fundus.  Later, 
the  deposit  of  pigment  goes  on  niore  rapidly,  and  the  net-work  of 
anastomosing,  dark,  irregular  figures  surrounds  the  macula  lutea 
in  a  steadily  contracting  circle. 

At  an  early  period  of  the  disease  there  begins  a  remarkable 
change  in  the  retinal  vessels.  Their  calibre  is  greatly  reduced 
by  a  peculiar  hyaline  thickern'ng  of  their  walls,  so  that  the  red 
column  of  blood  in  them,  especially  in  the  arteries,  appears  very 
thin. 

At  a  later  stage  the  optic  disc  and  the  surrounding  retina  pre- 
sent a  light-gray  opacity.  Perhaps  this  is  due  rather  to  a  change 
in  the  vitreous;  at  least  I  ha^'C  several  times  found  in  cases  of 
pigmentation  of  the  retina  a  rich  development  of  cells  in  the 
peripheral  part  of  the  vitreous.*  These  cells  represent  the  begin- 
ning of  membranous  and  fibrous  growths. 

*  Arch.  f.  Ophth.,  B.  v.  1,  pag.  103. 


PIGMENTATION   OF   THE    EETINA.  449 

The  choroid  may  remain  unaltered,  or  slight  changes  may  be 
visible  in  it.  Frequently  in  children  a  distinct  punctation  of  the 
equatorial  part  of  the  clioroid  is  seen  to  precede  by  years  the 
deposition  of  pigment  along  the  retinal  vessels.  In  other  cases, 
on  the  contrary,  I  have  observed  in  connection  with  hemeralopia  in 
children,  decided  contraction  of  the  large  retinal  arteries,  l)ut  only 
very  slight  pigment  deposits  along  some  of  the  peripheral  retinal 
vessels,  and  no  perceptible  choroidal  changes. 

In  old  cases,  in  addition  to  the  pigmentation  of  the  retina, 
bright  spots  of  various  sizes  are  sometimes  seen.  As  the  choroidal 
stroma  is  very  distinct  within  their  limits,  the  impression  which 
they  convey  is  that  the  e]>ithelial  layer  has  lost  its  pigment. 

Those  cases,  however,  in  which  the  choroidal  changes  are  very 
apparent,  even  though  the  participation  of  the  retina  is  evident 
from  the  pigmentation  of  its  vessels,  ought  rather  to  be  referred 
to  choroiditis. 

Frequently  in  the  later  stages  of  the  disease  very  peculiar 
forms  of  opacities  in  the  lens  and  vitreous  develop.  As  regards 
the  lens,  there  is  generally  a  punctated  posterior  polar  cataract, 
with  occasionally  a  few  radiating  opacities.  The  somewhat  rarer 
opacities  of  the  vitreous  consist  mostly  of  small,  gray,  rounded, 
movable  flakes  occasionally  provided  with  thread-like  processes. 

It  has  beeu  shown  that  pigmentation  of  the  retina  very  often 
occurs  in  connection  with  diseases  wdiose  history  is  very  different 
from  that  of  the  typical  pigment  degeneration  of  the  retina.  Let 
us  first  consider  how  pigmentation  of  the  retina  in  general  can 
take  place.  Choroiditis  is  a  frequent  cause  by  which  the  retina 
becomes  adherent  to  the  choroid  and  saturated  and  swollen  by  the 
fluid  exudates.  The  immediate  effect  is  the  destruction  of  the 
layer  of  rods  and  cones  within  the  limits  of  the  adhesions.  The 
other  nervous  elements  gradually  break  down,  while  the  connect- 
ive tissue  experiences  a  hypertrophic  growth. 

The^ radial  fibres  are  thickened  and  lengthened  and  their  outer 
halves  frequently  curved  upon  themselves,  thus  forming  a;n  intri- 
cate net-work.  When  this  degeneration  of  the  retina  has  taken 
place,  the  pigment  from  the  choroid  can  very  easily  penetrate  it. 
The  proliferating  choroidal  epithelium  penetrates  the  pervious 
substance  of  the  atrophied  retina,  and  it  will  be  accordingly  found 
filled  with  round  black  cells.     Or  the  choroidal  epithelium  breaks 


450  PIGMEXTATIOX   OF   THE   RETINA. 

down,  its  pigment  molecules  become  free,  and  are  carried  into  the 
retina  by  the  inflammatory  exudations.  This  process  may  be  de- 
scribed as  a  pigment  infiltration  of  the  retina.  The  pigment  may 
also  be  deposited  in  the  exudate  between  the  choroid  and  the  retina. 

H.  Miiller*  has  called  attention  to  the  mechanical  influence 
which  the  above  mentioned  growth  of  the  radial  fibres  may  exer- 
cise upon  the  choroidal  epithelium.  The  epithelium  is  displaced 
and  the  furrows  in  the  granular  layer  become  crowded  together. 

The  fact  being  established  that  pigment  does  penetrate  the 
retina,  the  questions  arise:  does  all  the  pigment  found  in  the 
retina  come  from  sources  external  to  itself?  and,  how  does  the 
pigmentation  of  the  retinal  vessels  occur?  The  two  questions  are 
intimately  connected.  H.  Midler  has  repeatedly  and  explicitly 
answered  the  first  in  the  affirmative,  and  seems  disposed  to  regard 
the  coloring  matter  of  the  blood  as  the  only  source,  aside  from 
the  choroidal  pigment,  from  which  the  pigment  found  in  the 
retina  can  come.  From  this  point  of  view  the  pigmentation  of 
the  retinal  vessels  must  be  regarded  rather  as  an  accident,  due, 
perhaps,  to  the  fact  that  the  pigment  adheres  to  the  walls  of  the 
vessels  more  easily  than  to  other  parts.  In  fact,  in  most  of  the 
cases  examined  anatomically  the  pigment  was  found  deposited  in 
all  the  layers  of  the  retina  and  not  limited  to  the  vessels. 

But,  in  view  of  the  ophthalmoscopic  appearances,  the  theory 
that  all  the  pigment  found  in  the  retina  originally  belonged  to 
the  choroid  is  not  tenable.  If  that  were  true,  the  choroidal  changes 
would  be  greater  than  is  really  the  case.  ]\loreover,  it  would  be 
difficult  to  understand  why  the  above  described  contraction  of  the 
retinal  vessels  always  precedes  the  pigment  degeneration  of  the 
retina. 

Anatomical  examination  also  shows  that  together  with  the  pig- 
mentation of  the  vessels  there  is  always  a  very  peculiar  change  in 
their  walls.  They  undergo  a  hyaline  thickening,  which  causes 
a  contraction  of  their  calibre  and  finally  an  obliteration  q^  their 
finer  branches.  The  same  effect  may  be  caused  by  a  hypertrophy 
of  the  connective  tissue  of  the  vessels.  They  become  reduced  to 
mere  fibrous  strings,  and  disappear  in  the  tissue  of  the  retina. 

On  the  one  hand,  it  is  shown  that  choroiditis  may  cause  pig- 

*  WiJrzburger  med.  Zeitschrift,  B.  iii.  pag.  252, 


PIGMENTATION   OF   THE   RETINA.  451 

mentation  of  the  retina ;  on  the  other  hand,  however,  the  reports 
of  all  the  anatomical  examinations  of  cases  which  during  life  had 
presented  the  ophthalmoscopic  and  clinical  symptoms  of  retinitis 
pigmentosa,  agree  in  this,  that  there  existed  greater  or  less  changes 
in  the  choroidal  epithelium.  It  appears,  therefore,  that  the  an- 
swer respecting  the  source  of  the  pigment  in  the  retina  is  that  in 
some  way  it  must  come  from  the  pigment  epithelium  of  the  uvea. 
If  the  growing  choroidal  epithelium  has  once  penetrated  the 
retina,  it  is  likely  that  the  growth  may  continue  within  that 
membrane  until  it  contains  more  pigment  than  has  been  lost  by 
the  choroidal  epithelium. 

Certain  conditions  which  I  have  previously  described,*  in 
which  it  was  evident  that  the  pigmentation  of  the  retinal  vessels 
could  not  have  proceeded  from  the  choroid,  are  probably  to  be 
explained  by  assuming  some  portion  of  the  uvea  other  than  the 
choroid  as  the  source  of  the  pigment.  The  case,  as  is  true  of 
most  anatomical  examinations,  was  not  one  of  typical  torpor 
retinre  Avith  pigmentation  of  the  retina.  There  existed  iritis, 
atrophy  of  the  nervous  elements,  excavation  of  the  optic  nerve, 
and  besides  all  this  there  were  in  the  region  of  the  ciliary  body 
peculiar  changes  which  I  did  not  then  particularly  describe,  for 
the  reason  that  I  was  in  doubt  as  to  their  nature.  But  now,  after 
repeated  examination  of  the  preparation  which  I  still  possess,  I 
think  these  changes  in  the  ciliary  body  should  be  particularly 
described,  as  it  is  possible  that  just  here  was  the  source  from 
which  emanated  the  pigment  found  in  the  retinal  vessels. 

There  remained  upon  the  vitreous,  after  it  was  drawn  away 
from  the  corpus  ciliare,  a  pigmentation  which,  magnified  about  100 
times,  showed  a  net-work  having  long  meshes,  and  appeared  as 
if  made  up  of  delicate,  pigmented  vessels,  whose  larger  trunks  were 
directed  toward  the  ora  serrata.  In  fact,  in  this  pigmented  net- 
work some  fine  capillary,  non-pigmented  vessels  could  be  seen. 

It  appeared  to  rae  as  if  a  new  vascular  net-work  connected 
with  the  retina  had  developed  in  the  pars  ciliaris.  If  this  inter- 
pretation of  the  condition  be  the  true  one,  the  pigment  epithelium 
of  the  ciliary  body  must  have  been  the  source  of  the  pigment 
found  on  the  retinal  vessels. 

*  Arch.  f.  Opbth.,  B.  ix.  1,  pag.  205. 


452  PIGMENTATION   OF   THE   EETINA. 

The  deposition  of  pigment  along  the  vessels  does  not  always 
appear  to  be  continuously  progressive,  but  the  deposit  takes  place 
at  intervals  with  free  spaces  between.  This  peculiar  disposition 
of  the  pigment  is  occasionally  observed  during  ophthalmoscopic 
examination  of  the  vessels  upon  the  surface  of  the  optic  disc.  It 
has  also  been  demonstrated  anatomically,  and  first  by  Donders.* 

Since  as  yet  but  few  eyes  in  which  retinitis  pigmentosa  has 
been  recognized  during  life  have  been  examined  anatomically,  it 
is  perhaps  well  to  describe  here  briefly  the  results  of  such  exami- 
nations. 

In  a  case  which  had  long  been  under  observation,  Dondersf 
found  the  retina  adherent  to  the  choroid  at  three  or  four  places 
where  it  was  most  pigmented,  so  that  it  was  difficult  to  separate 
the  two.  It  appeared  as  if  there  were  in  these  places  an  exudate 
filled  with  pigment,  which  tore  apart  when  the  two  membranes 
■were  separated,  so  that  one  part  remained  on  the  retina  and  the 
other  on  tiie  choroid.  In  these  places  the  pigment  which  per- 
meated the  retina  was  continuous  with  that  in  the  choroid.  But 
over  a  surface  of  more  than  a  square  centimetre  no  such  connec- 
tion could  be  found.  It  was  incredible  that  all  the  pigment  could 
have  infiltrated  the  retina  fipm  these  adherent  spots,  for  in  the 
immediate  neighborhood  of  these  exudations  the  choroidal  pig- 
ment epithelium  was  quite  uniform  and  normal. 

The  second  case  was  examined  by  Leber|  ophthalmoscopically 
shortly  before  the  death  of  the  patient.  The  subsequent  ana- 
tomical appearances  were  as  follows :  there  were  atrophy  of  the 
nervous  elements,  hyperplasia  of  the  connective  tissue,  thickening 
and  sclerosis  of  the  walls  of  the  vessels,  reticulated  pigmentation 
of  all  the  layers  following  principally  the  vessels,  great  changes 
in  the  pigment  epithelium,  numerous  excrescences  of  the  hyaline 
membrane,  and  small  circumscribed  deposits  of  fatty,  degenerated 
exudate  between  the  choroid  and  the  retina. 

Lastly,  Landolt§  reports  two  cases  in  which  repeated  previous 
ophthalmoscopic  examination  had  revealed  the  typical  appearances. 

*  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  141. 

f  Maes,  Over  torpor  retina,  Zweiter  Jahresbericht  der  Utrechter  Augen- 
klinik,  18G1,  pag.  263. 

X  Arch.  f.  Ophth.,  B.  xv.  3. 
2  Ibid.,  B.  xviii.  1,  pag.  325. 


PIGMENTATION   OF   THE    RETINA.  453 

The  principal  anatomical  changes  were  an  almost  complete  absence 
of  the  nervous  elements,  including  the  rods  and  cones,  and  hyper- 
plasia of  both  the  general  connective  tissue  and  that  of  the  vessels, 
which  accordingly  were  much  thickened,  their  calibre  reduced,  and 
their  finest  branches  completely  obliterated.  In  the  walls  were 
great  quantities  of  pigment,  which  probably  had  partly  wandered 
and  partly  been  formed  there,  part  contained  in  cells  and  part  free. 
The  pigment  of  the  epithelial  layer  had,  for  the  most  part,  wan- 
dered away  from  it,  and  was  collected  at  places  in  the  retina  in  the 
typical  manner,  as  determined  by  the  course  of  the  vessels. 

The  anatomical  conditions,  considered  in  connection  with  the 
functional  disturbances  and  the  course  of  the  disease,  show  the  cor- 
rectness of  Donders'*  early  opinion,  that  the  pigmentation  of  the 
retina  is  a  secondary  matter,  and  not  the  essential  element  of  the 
process.  Donders  arrived  at  this  conclusion  from  the  circumstance 
that  it  is  sometimes  possible  to  demonstrate  a  loss  of  perception 
beyond  the  limits  of  the  pigmented  portion  of  the  retina  in  the 
direction  of  the  macula  lutea.  His  method  of  doing:  this  was  a 
very  ingenious  one,  and  consisted  in  throwing  with  the  ophthal- 
moscope a  very  small  image  of  a  flame  upon  the  various  parts  of 
the  retina,  and  directing  the  patient  to  tell  at  what  places  he  could 
see  it. 

Transmission  from  parents  is  an  important  element  in  the  eti- 
ology of  the  disease.  But  several  children  in  the  same  family  may 
suffer  from  it  without  the  parents  having  been  so  affected.  Under 
these  circumstances,  deafness  frequently  exists  as  a  complication. 

The  disease  appears  to  be  more  frequent  with  deaf-mutes  and 
idiots  than  with  any  other  class  of  persons.  Frequently  other 
anomalies  of  development  co-exist,  such,  for  instance,  as  supernu- 
merary fingers  and  toes.f  Liebreich  has  called  attention  to  the 
fact  that  in  many  cases  the  parents  were  blood  relations.^  More 
comprehensive  statistics  with  reference  to  the  matter  of  consan- 
guinity are  certainly  desirable. 

The  disease  frequently  occurs  congenitally.     Children  are  born 


*  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  148. 

t  Horing,  Klin.  Monatsbl.,  1864,  pag.  233,  und  ISfio,  pag.  236  ;  Stor,  ibid., 
1865,  pag.  23. 

X  Deutsche  Klinik,  1861,  No.  6. 


454  PIGMENTATION   OF   THE   RETINA. 

with  pigmented  retinas,  and  at  the  same  time  frequently  with  eyes 
that  are  too  small,  and  either  absolutely  blind  or  with  only  a 
feeble  perception  of  light.  Under  such  circumstances,  nystagmus 
generally  develops. 

Hemeralopia  generally  dates  from  childhood  or  about  the  time 
of  puberty.     Both  eyes  are  affected,  almost  without  exception.* 

The  course  of  the  disease  is  exceedingly  slow.  From  20  to  40 
years  may  intervene  between  the  appearance  of  hemeralopia  and 
eventual  blindness.  It  is  not  certain  whether  all  cases  go  on  to 
complete  blindness  or  remain  stationary  at  some  stage  of  their 
development. 

As  supplemental  to  the  above  description  of  typical  pigmenta- 
tion of  the  retina,  it  should  be  mentioned  that  cases  occur  which 
agree  with  it  in  many  points,  but  vary  from  it  in  other  essential 
respects. 

In  the  first  place,  hemeralopia  may  occur  under  various  condi- 
tions without  pigmentation  of  the  retina.  Aside  from  those  cases 
in  which  hemeralopia  is  observed  as  a  symptom  of  some  acute 
pathological  process  in  persons  hitherto  healthy,  and  which  repre- 
seift  a  peculiar  form  not  belonging  in  this  place,  we  must  mention, 
first,  those  rather  rare  cases  in  which  congenital  amblyopia  exists 
without  any  ophthalmoscopic  changes.  By  good  illumination  cen- 
tral vision  may  be  perfect  or  slightly  defective,  while  by  a  weaker 
illumination  the  torpor  retinse  is  manifested  by  a  very  consider- 
able diminution  of  central  vision,  and  generally  also  by  a  contrac- 
tion of  the  visual  field.  Exceptionally,  the  torpor  is  greater  for 
central  than  for  slightly  eccentric  vision.  This  condition  appears 
generally  to  remain  stationary,  and  the  prognosis  is  better  than 
when  pigmentation  exists.  The  relationship  between  this  form 
and  that  accompanied  by  pigmentation  is  shown  by  the  fact  that, 
among  several  children  of  the  same  parents,  some  will  have  the 
one  form  of  hemeralopia  and  some  the  other. 

There  occur  rare  cases  in  which  hemeralopia,  due  to  torpor 
retinae,  with  defective  eccentric  vision,  or  contraction  of  the  visual 

*  In  a  case  described  by  Pedraglia  (Klin.  Monatsbl.,  1865,  pag.  114),  there 
was  complete  choroidal  atrophy  at  several  places,  and  for  this  reason  it  should 
be  regarded  as  one  of  choroiditis  with  pigmentation  of  the  retina.  In  a  case 
observed  by  Donders  (E.  Baumeister,  Arch.  f.  Ophth.,  B.  xix.  2,  pag.  261), 
there  was  at  least  a  trace  of  pigment  development  upon  the  other  healthy  eye. 


HEMOERHAGES   IN   THE   RETINA.  455 

field,  develops  at  a  later  period  of  life,  without  any  traces  of  pig- 
mentation of  the  retina  or  any  other  apparent  changes,  such  as 
contraction  of  the  arteries  and  gray  discoloration  of  the  optic 
nerve.  In  similar  cases  Von  Graefe  observed  a  development  of 
pigment  in  the  retina  after  the  lapse  of  several  years. 

As  a  result  of  syphilitic  retinitis  I  have  observed  marked  torpor 
retinse,  in  connection  with  diffuse  opacities  of  the  vitreous,  a 
whitish  discoloration  of  the  optic  disc,  and  slight  changes  in  the 
periphery  of  the  choroid  (white  punctiform,  but  never  black 
spots),  but  without  a  trace  of  pigmentation  in  the  reti  na.  Forster's* 
observations,  however,  indicate  that  in  these  cases  pigmentation  of 
the  retina  may  occur  at  a  later  period  of  the  disease. 

But  even  with  evident  pigmentation  of  the  retina  some  cases 
deviate  essentially  from  the  usual  type  of  the  disease.  This  is 
true  of  the  cases  described  by  Von  Graefe,t  in  which  there  existed 
an  annular  defect  in  the  visual  field,  and  beyond  the  peripheral 
margin  of  this  ring  eccentric  vision  was  still  retained.  The  pig- 
mented portion  of  the  retina  had  lost  its  power  of  perception,  but 
the  conducting  function  of  the  nerve  fibres  running  to  the  periphery 
was  retained.  This  condition  can  be  explained  on  the  assumption 
that  the  pathological  process  first  destroys  the  external  perceptive 
retinal  layers. 

In  other  cases  of  unusual  forms  of  retinitis  pigmentosa,  ambly- 
opia may  be  caused  at  an  early  period  of  the  disease  by  irregular, 
roundish,  black  masses  of  pigment  which  occupy  the  position  of 
the  macula  lutea. 

HEMORRHAGES   IN   THE   RETINA. 

Hemorrhages  in  the  retina  are  frequently  seen  ophthalmoscop- 
ically,  for  they  occur  both  as  an  independent  disease,  and  accom- 
panying various  inflammatory  processes. 

The  hemorrhages  are  most  frequent  in  that  part  of  the  retina 
lying  posterior  to  the  equator.  Frequently  they  are  numerous, 
large,  and  crowded  together,  and  in  such  cases  the  macula  lutea  is 
seldom  spared.     It  may,  however,  happen  that  the  entire  hemor- 

*  Arch.  f.  Ophth.,  B.  xx.  1,  pag.  33,  und  H.  Magnus,  Ophthalmoscopischer 
Atlas,  Taf.  xiii.  Fig.  1,  pag.  7G. 

t  Arch.  f.  Ophth.,  B.  iv.  2,  pag.  200. 


456  HEMORRHAGES   IN   THE   RETINA. 

rhage  consists  of  only  some  few  pnnctiform  extravasations,  which, 
however,  unluckily  occupy  exactly  the  position  of  the  macula  lutea. 
The  form  of  the  extravasations  varies  with  the  place  in  which 
they  occur.  Near  the  optic  disc,  where  the  nerve-fibre  layer  is 
relatively  thick,  they  assume  an  elongated  shape,  radiating  in  the 
direction  of  the  fibres.  They  spread  more  in  the  middle  layers 
of  the  retina,  and  for  that  reason  appear  as  circular  patches.  A 
rupture  of  the  hemorrhage  may  occur  on  either  surface  of  the 
retina.  If  it  happen  on  the  outer  surface,  a  layer  of  blood  spreads 
out  between  the  retina  and  the  choroid.  If  the  rupture  be  through 
the  internal  limiting  membrane,  the  effusion  of  blood  is  into  the 
vitreous  body. 

Exceptionally  it  happens,  and  principally  in  the  neighborhood 
of  the  macula  lutea,  that  the  blood  spreads  out  between  the  retina 
and  the  vitreous.  In  such  cases  the  large  retinal  vessels  are  seen 
to  disappear  beiiind  the  sharply  defined  margin  of  the  extravasa- 
tion which  covers  them. 

The  color  of  the  retinal  hemorrhages  appears  to  be  modified  to 
some  degree  by  that  of  the  fundus.  Against  the  lighter  back- 
ground of  a  weakly  pigmented  choroid  the  blood-patches  appear 
of  a  brighter  red,  while  against  a  darker  choroid  they  are  likewise 
darker. 

Retinal  hemorrhages  are  always  very  slowly  absorbed,  requiring 
from  4  to  6  weeks,  even  under  the  most  favorable  conditions,  as, 
for  instance,  when  they  have  occurred  after  an  iridectomy  in  glau- 
coma. More  extensive  hemorrhages  may  remain  from  6  to  8 
months,  or  even  longer.  As  a  rule,  the  blood-patches  grow  grad- 
ually paler,  contract,  or  break  up  into  several  parts. 

The  extravasations  somewhere  between  the  third  and  the  sixth 
week  frequently  show  a  remarkable  alteration,  becoming  changed 
to  glistening  white  patches.  The  anatomical  process  by  which 
this  is  brought  about  is  not  well  understood.  It  may  be  due  to 
a  varicose  hypertrophy  of  the  nerve  fibres,  or  to  fatty  degeneration 
of  the  broken-down  nerve  elements,  or  to  a  metamorphosis  of  the 
effused  blood-corpuscles.  Occasionally  these  same  changes  are 
observed  to  take  place  in  the  optic  nerve  itself. 

It  is  very  seldom  that  dark,  pigmented  spots  remain  after 
retinal  hemorrhages.  In  the  course  of  time  they  generally  dis- 
appear without   leaving  any  trace,  but  exceptionally  choroidal 


HEMORRHAGES   IN   THE   RETINA.  457 

changes  appear  as  the  hemorrhages  are  absorbed.  These  changes 
may  be  caused  by  the  rupture  of  small  hemorrhages  through  the 
external  limiting  membrane  and  the  cifusion  of  a  small  quantity 
of  blood  upon  the  choroidal  epithelium.  It  seems  likewise  prob- 
able that  retinal  hemorrhages  may  cause  inflammatory  processes 
in  the  external  layers,  followed  by  hypertrophy  of  the  radial  fibres, 
and  subsequent  choroidal  changes. 

The  disturbances  of  vision  depend,  for  the  most  part,  upon  the 
fact  that  the  rays  of  light  are  absorbed  by  the  effusion  before 
they  reach  the  sensitive  layer.  The  destruction  of  tissue  caused 
by  the  hemorrhages  is  still  more  important,  and  it  almost  of 
necessity  takes  place  when  such  an  accident  occurs  in  so  delicate 
a  membrane  as  the  retina.  Less  damage  seems  to  be  done  by 
hemorrhages  occurring  near  the  optic  nerve,  where  the  blood  can 
spread  out  in  a  direction  parallel  to  the  nerve  fibres.  In  the 
deeper  layers  of  the  retina,  however,  a  hemorrhage  can  scarcely 
occur  without  tearing  the  delicate  nerve  fibres  which  connect  the 
ganglion  cells  with  the  external  layers. 

For  every  hemorrhage  there  is  therefore  a  loss  of  eccentric 
vision,  or  a  defect  in  the  visual  field,  which,  if  in  the  region  of  the 
macula  lutea,  is  very  annoying.  If  the  hemorrhages  be  in  the 
periphery,  they  can  be  discovered  only  by  careful  examination, 
and  must  be  very  extensive  to  cause  any  annoyance.  A  slight 
hemorrhage,  if  it  occur  at  the  macula  lutea,  may  therefore  interfere 
greatly  with  vision,  while  if  that  part  be  spared,  very  extensive 
hemorrhages  in  the  equatorial  part  may  cause  no  great  annoyances. 
But  it  is  unfortunate  that  retinal  hemorrhages  are  most  frequent 
just  in  the  region  of  the  macula  lutea. 

Diseases  of  the  optic  nerve  frequently  develop  in  consequence 
of  numerous  and  extensive  hemorrhages.  A  remarkable  sinuosity 
of  the  small  vessels  visible  upon  the  optic  disc  often  remains,  with 
signs  of  an  atrophic  degeneration  in  the  nerve,  such  as  a  whitish 
color,  and  slight  excavation.  This  may  happen  without  vision 
growing  any  poorer.  If  numerous  hemorrhages  have  broken  up 
a  great  number  of  the  delicate  fibres  of  the  retina,  a  secondary 
atrophy  may  extend  back  to  the  optic  nerve  without  causing  any 
new  symptoms  of  loss  of  vision. 

In  another  class  of  cases,  a  glaucomatous  condition  develops 
after  extensive  retinal  hemorrhages.     The  eyeball  becomes  hard, 

30 


458  HEMORRHAGES   IN   THE   RETINA. 

and  there  is  excavation  of  tlie  optic  nerve.     The  course  of  the 
disease  may  be  either  with  or  without  severe  pains. 

Retinal  hemorrhages,  as  an  independent  disease,  generally  do 
not  occur  till  late  in  life.  They  are  most  frequent  after  the  fif- 
tieth year.  They  may  occur  at  any  time  of  life  as  a  symptom  of 
retinitis,  or  from  traumatic  causes.  Diseases  of  the  heart  or  vas- 
cular system,  such,  for  instance,  as  hypertrophy  of  the  left  ventricle 
or  rigidity  of  the  arteries,  may  cause  them.  In  many  cases  con- 
gestion of  the  head  is  the  exciting  cause.  Atheromatous  degen- 
eration of  the  retinal  arteries  has  been  described  and  represented 
by  Wedl.*  Manzf  also  found,  in  a  case  of  hemorrhage  in  the 
retina,  a  sclerosis  and  atheromatous  degeneration  of  its  arteries. 
It  is  remarkable  that  the  ophthalmoscopic  appearances  give  no 
hint  for  the  diagnosis  of  this  probably  not  uncommon  condition. 
Exceptionally,  retinal  hemorrhages  occur  as  one  of  the  symptoms 
in  purpura  hoemorrhagica.  It  should  be  mentioned  finally  that 
they  frequently  occur  after  iridectomy  in  inflammatory  glaucoma. 
These  hemorrhages,  however,  seldom  interfere  with  direct  vision. 

The  prognosis  depends  upon  the  degree  and  the  cause  of  the 
disturbances  of  vision. 

Peripheral  hemorrhages,  which  leave  the  macula  lutea  intact, 
cause  slight  loss  of  vision,  and  admit  of  complete  recovery.  If 
the  macula  lutea  be  actually  involved,  no  great  improvement  can 
be  expected,  even  after  the  resorption  of  the  effused  blood.  Those 
rare  effusions,  however,  which  spread  out  in  front  of  the  macula 
lutea,  between  it  and  the  vitreous  body,  interfere  greatly  with 
vision,  but  admit  of  complete  recovery. 

It  is  to  be  remembered  that  retinal  hemorrhages  not  infre- 
quently recur. 

The  prognosis  is  unfavorable  in  those  cases  in  which  glauco- 
matous symptoms  develop.  Vision  is  generally  already  greatly 
damaged  by  the  hemorrhages,  and  the  secondary  glaucoma  is 
usually  of  a  malignant  type,  which  is  not  benefited  by  iridec- 
tomy. 

Rest  and  derivative  treatment  are  the  principal  indications.  All 
straining  of  the  eyes,  all  violent  bodily  exertion,  everything  which 

*  Atlas  der  path.  Anat.  des  Auges,  Retina  und  Opticus,  Taf.  i.  Fig.  5. 
f  Bericht  der  naturforschenden  Gesellschaft  zu  Freiburg,  1860. 


EETIXITIS.  459 

accelerates  the  circulation  or  causes  congestion  of  the  head,  must 
be  avoided. 

The  usual  means  employed  to  assist  the  resorption  of  the 
effusions  are  the  elixir  acid.  Halleri,*  local  bleeding  from  the 
temple,  cathartics,  etc. 

The  proposition  to  diminish  the  blood  pressure  by  digitalis,  or 
to  excite  a  contraction  of  the  small  vessels  by  ergot,  cannot  be 
regarded  as  of  practical  value. 

RETINITIS. 

The  diagnosis  of  retinitis  can  be  made  only  with  the  ophthal- 
moscope. The  subjective  symptoms  are  not  so  characteristic  that 
the  diagnosis  can  be  made  from  them.  There  are  no  external 
visible  changes. 

The  general  ophthalmoscopic  signs  of  retinitis  are  clouding  of 
the  retina  and  hyperemia  of  its  vessels.  The  clouding  is  gener- 
ally most  intense  at  the  intraocular  extremity  of  the  optic  nerve, 
and  hides,  therefore,  the  boundary-line  of  its  place  of  entrance. 
The  inner  optic-nerve  sheath,  the  dark  choroidal  ring,  and  the 
white  scleral  stripe  which  is  often  visible  between  them,  lie  behind 
the  retina,  and  are  therefore  hidden  when  it  becomes  opaque.  If 
this  clouding  be  limited  principally  to  the  inner  layers,  fine  radi- 
ating strife  may  often  be  seen  about  the  optic  nerve. 

The  hypersemia  is  likewise  greatest  at  the  intraocular  extremity 
of  the  optic  nerve.  The  numerous  fine  vessels  which  in  the 
normal  condition  give  a  rosy  tint  to  the  optic  disc,  cause,  when 
fully  distended,  an  intense  redness  of  the  spot;  but  the  hypereemla 
is  most  noticeable  in  the  large  vessels  of  the  retina,  especially  its 
veins.  Since  the  vessels  are  more  distensible  in  the  longitudinal 
than  in  the  transverse  direction,  they  become  not  only  dilated 
but  also  elongated.  Ophthalmoscopically,  therefore,  they  appear 
thicker,  and  at  the  same  time  exceedingly  sinuous,  their  curves 
being  both  in  the  plane  of  the  retina  and  perpendicular  to  it. 
The  deeper-lying  ones,  when  there  is  at  the  same  time  a  dense 
clouding  of  the  retinal  substance,  are  veiled  by  it  or  absolutely 
hidden,  so  that  the  vessels  appear  as  if  interrupted,  while  the 

*  This  preparation  consists  of  1  part  sulphuric  acid  and  3  parts  spirits  of 
wine.     Dose,  5  to  20  drops. —  Translator. 


460  RETINITIS. 

superficial  curves,  Avhicli  are  covered  by  very  little  retinal  sub- 
stance, are  sharply  defined  and  intensely  red. 

These  sinuosities  may  also  occur  while  the  retina  is  absolutely 
transparent,  in  which  case  they  indicate  oedema  of  the  retina. 

The  arteries  are  generally  not  dilated ;  indeed,  they  are  often 
smaller  than  in  the  normal  condition,  which  may  be  due  to  the 
fact  that  the  swelling  and  liypersemia  of  the  tissues  extend  into 
the  intraocular  end  of  the  optic  nerve  as  far  as  the  lamina  crib- 
rosa.  If  a  swelling  of  the  tissues  occur  at  this  point,  surrounded 
as  it  is  by  the  unyielding  scleral  ring,  a  compression  of  the  central 
vessels  may  be  caused,  the  immediate  consequence  of  which  will 
be  both  anaemia  of  the  arteries  and  hypersemia  of  the  veins. 

Venous  hypera^mia  and  cloudy  swelling  are  the  essential  char- 
acteristics of  retinitis,  but  the  ophthalmoscopic  picture  is  often 
varied  by  a  series  of  other  changes. 

Hemorrhages  are  here  to  be  mentioned  as  a  frequent  symptom 
in  retinitis,  and  yet  in  many  cases  they  are  absolutely  wanting. 

Next  should  be  mentioned  certain  white  spots,  which  sometimes 
occur  in  the  form  of  dots,  sometimes  have  nearly  the  diameter  of 
the  optic  disc,  or,  by  the  coalescence  of  several  such,  may  form 
large  irregular  figures.  These  changes  often  present  a  very  pecu- 
liar aj>pearance  in  the  region  of  the  macula  lutea. 

Fine  white  points  are  there  often  arranged  in  peculiar  stellate 
groups,  appearing  as  if  placed  upon  lines  radiating  from  the 
fovea  centralis.  More  rarely  there  are  broad  bright  stripes,  which 
converge  toward  the  same  point. 

Probably  this  singular  grouping  is  due  to  the  peculiar  arrange- 
ment of  the  radiating  fibres,  which  in  the  macula  lutea  do  not 
run  perpendicularly  through  the  thickness  of  the  retina,  bu^  in 
such  a  manner  that  upon  their  way  from  the  inner  to  the  outer 
layers  they  all  converge  toward  the  centre  of  the  macula  lutea. 
Upon  a  flat  section  of  the  macula  lutea  this  radiating  arrangement 
of  the  external  fibrous  layer  may  be  distinctly  seen.* 

This  stellate  punctation  is  most  frequently  seen  in  retinitis 
albuminurica,  but  frequently  also  in  other  forms  of  retinitis  not 
dependent  upon  albuminuria. 

*  Fr.  Merkel,  IJeber  die  macula  lutea  des  Menschen,  Leipzig,  1870,  Taf.  i. 
Fisr.  11. 


RETINITIS.  461 

Quite  rarely  there  occur  very  distinct  cloudings,  radiating  in 
the  direction  of  the  nerve  fibres,  and  probably  due  to  changes 
occurring  at  the  inner  extremities  of  these  fibres. 

The  observations  which  have  been  made  in  this  matter  have 
been  mostly  in  connection  with  retinitis  due  to  albuminuria;  still, 
two  cases  described  by  E.  v.  Jaeger*  and  Mauthnerf  as  "  retinitis 
with  greenish  stripes"  show  that  ophthalmoscopic  changes  de- 
pendent upon  morbid  processes  in  the  extremities  of  the  radiating 
fibres  may  occur  without  this  complication. 

The  retinal  vessels,  especially  the  arteries,  in  many  cases  of 
retinitis,  and  most  frequently  in  the  albuminuric  form,  appear  to 
be  accompanied  by  bright  Avhite  stripes  close  to  and  on  both  sides 
of  the  red  blood-vessels,  causing  them  to  appear  smaller  and  less 
distinct.  Evidently  this  appearance  is  due  to  a  thickening  of  the 
adventitial  coat  of  the  vessels. 

The  disturbances  of  vision  in  retinitis  vary  greatly,  and  often 
stand  in  no  evident  relation  to  the  ophthalmoscopic  appearances. 
Two  cases  presenting  the  appearance  of  very  similar  changes  may 
be  accompanied,  the  one  with  great  diminution  of  vision,  the 
other  with  but  very  little;  so,  too,  in  one  case  the  visual  field  re- 
mains free,  in  another  it  shows  a  greater  or  less  defect,  without  its 
being  possible  in  all  cases  to  find  ophthalmoscopically  an  explana- 
tion for  this  behavior.  We  can  only  conclude  that  very  striking 
ophthalmoscopic  changes  may  occur  in  the  retina  without  essen- 
tially affecting  the  nervous  elements,  while,  inversely,  considerable 
disturbances  of  the  function  of  the  nerves  may  be  induced  by 
changes  not  to  be  seen  with  the  ophthalmoscope. 

The  complaints  of  the  patients  refer  mostly  to  indistinctness 
of  vision.  Often,  but  not  always,  there  is  photophobia,  so  that 
dazzling  is  caused  by  full  daylight. 

Micropsia  is  a  very  remarkable  symptom,  which  not  infre- 
quently develops  in  the  later  stages  of  retinitis.  Von  Graefe| 
observed  this  phenomenon  first  in  syphilitic  retinitis,  but  it  also 
occurs  in  other  forms.  The  micropsia  often  varies  in  degree  on 
different  portions  of  the  retina,  and  is  therefore  connected  with 

*  Ophthalmoscopischer  Handatlas,  Taf.  xv.  Fig.  71. 
f  Lehrbuch  der  Ophthalmoscopie,  pag.  361. 
+  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  215. 


462  RETINITIS. 

metamorphopsia,  so  that  objects  appear  not  only  diminished,  but 
at  the  same  time  distorted,  slanting,  and  crooked. 

The  degree  of  the  micropsia  may  be  easily  determined  by  pro- 
voking double  images  of  Snellen's  test  letters,  standing  one  above 
the  other,  by  means  of  a  prism  refracting  vertically.  In  some  cases 
I  have  been  able  in  this  way  to  demonstrate  a  diminution  of  the 
micropsia  simultaneously  with  a  gradual  improvement  of  vision. 

Since  we  cannot  assume  as  an  explanation  for  this  form  of 
micropsia  either  an  actual  diminution  of  the  retinal  images  or  a 
false  estimation  of  their  size,  nothing  remains  but  to  refer  the 
jihenomenon  to  the  loss  of  a  certain  proportion  of  the  sensitive 
elements  in  the  macula  latea. 

Retinitis  occurs  most  frequently  as  the  consequence  of  some  con- 
stitntional  disease.  The  ophthalmoscope  has  shown  that  Bright's 
disease  and  syphilis  are  the  most  frequent  causes;  leucaemia  should 
also  be  mentioned.  Anatomical  examinations*  have  likewise 
shown  it  to  be  due  to  septic  processes  in  the  soft  parts,  to  gan- 
grenous bronchitis,  purulent  pericarditis,  pleuritis,  or  peritonitis, 
and  to  senile  gangrene.  The  anatomical  changes  in  retinitis  septica 
consist  in  hemorrhages,  and  small  white  spots  formed  by  thickened 
nerve  fibres  and  fatty  degenerated  connective-tissue  corpuscles. 

For  the  most  part,  the  etiology  of  retinitis  is  distinctly  indicated 
by  the  form  of  the  disease,  and,  as  the  disease  has  very  varied 
clinical  histories,  it  is  desirable  to  distinguish  clearly  these  different 
forms. 

The  simplest  form  is  that  in  which  the  retina,  near  the  optic 
nerve,  is  moderately  clouded  and  swollen,  while  only  slight 
changes,  such  as  redness,  clouding,  etc.,  can  be  recognized  upon 
the  optic  disc.  The  retinal  veins  are  more  sinuous.  Hemor- 
rhages very  rarely  occur.  Exposure  is  not  infrequently  the  cause 
of  such  cases, — for  instance,  sudden  wetting  when  the  body  is 
warm,  cooling  the  head,  etc.  It  also  occurs  simultaneously  with 
other  rheumatic  symptoms.  With  proper  treatment  it  may  run  a 
favorable  course  in  a  few  months.  Leeches  upon  the  temple, 
a  mild  depurative   and   diaphoretic  treatment,  protection  from 

*  Dr.  M.  Eoth,  Virchow's  Arch.,  B.  Iv.,  unci  Deutsche  Zeitsch.  f.  Chirurgie, 
B.  i.  5,  pag.  471. 


RETINITIS   HEMORRHAGICA, — SYPHILITICA. 


463 


exposure  to  cold,  and  complete  rest  for  the  eyes,  generally  prove 
sufficient. 

Another  group  of  cases  is  characterized  by  frequent  hemor- 
rhages, which  accompany  the  other  symptoms  of  retinitis.  The 
individuals  affected  are  generally  those  suffering  from  some  anom- 
alies of  the  circulation.  Plethora  abdominalis  and  habitual 
congestion  of  the  head  are,  therefore,  the  most  frequent  causes 
of  this  form  of  disease,  which,  on  account  of  the  frequency  of 
the  hemorrhages,  may  be  called  Retinitis  hsemorrhagica.  The 
appearances  in  this  form  are  modified  in  a  very  peculiar  manner 
by  the  preponderance  of  the  hemorrhages.  All  that  has  been  said 
in  reference  to  the  course  and  prognosis  of  retinal  hemorrhages  is 
also  applicable  here.  The  prognosis  of  retinitis  hemorrhagica  is, 
therefore,  generally  quite  favorable.  Above  all  things,  the  be- 
liavior  of  the  macula  lutea  is  to  be  observed,  as  it  seldom  escapes 
when  the  hemorrhages  become  frequent. 

The  disorganization  of  retinal  tissue  caused  by  the  hemorrhages 
is  irreparable;  moreover,  the  inflammatory  process  appears  to  be 
much  protracted  by  the  presence  of  the  extravasated  blood.  I 
have  seen  cases  in  which,  after  one  and  a  half  or  two  years,  there 
were  still  opacity  of  the  retina  and  hyperemia  of  the  veins. 

The  treatment  should  be  derivative,  with  especial  attention  to 
any  existing  disturbances  of  the  circulation  in  distant  organs. 

Syphilitic  retinitis  generally  occurs  simultaneously  with  other 
local  symptoms  of  constitutional  syphilis,  or  follows  shortly  after 
them.     Often,  but  not  always,  it  occurs  in  both  eyes. 

It  is  characterized  ophthalmoscopically  principally  by  a  diffuse 
gray  clouding,  which  extends  from  the  optic  disc  over  a  consid- 
erable portion  of  the  retina,  and  particularly  along  the  larger 
vessels.  The  veins  are  only  moderately  dilated  and  curved;  the 
optic  disc,  too,  generally  appears  but  slightly  clouded ;  it  is  only 
seldom  that  it  shows  any  considerable  swelling.  Hemorrhages 
are  not  generally  present,  but  may  exceptionally  occur.  Irregu- 
larly shaped  dull  patches  are  often  observed  in  the  retina. 

A  very  frequent  complication  is  a  delicate  clouding  of  the  vit- 
reous body,  when  iritis  or  choroiditis  syphilitica  is  present,  or  even 
without  these.     It  is  at  first  often  so  fine  that  its  ophthalmoscopic 


464  RETINITIS   SYPHILITICA. 

diagnosis  without  atropine  mydriasis  is  scarcely  possible ;  at  a  later 
stage  it  becomes  very  distinct. 

Aside  from  the  difficulty  of  recognizing  this  condition  of  the 
vitreous  body,  its  existence,  when  established,  raises  further  ques- 
tions. 

The  changes  in  the  retina,  as  Mauthner*  correctly  remarks,  are 
frequently  so  slight  as  to  appear  like  delicate  vitreous  membranes 
projecting  from  the  retina.  If  now  one  has  satisfied  himself  of 
the  existence  of  such  a  clouding,  he  may  still  remain  in  doubt  as 
to  whether  retinitis  exists.  The  hypersemia  of  the  retinal  veins, 
and  the  possible  presence  of  hemorrhages,  or  other  changes,  fur- 
nish, then,  the  points  upon  Avhich  to  rely  in  making  the  diag- 
nosis. 

Occasionally  one  sees  also  in  syphilitic  retinitis  a  swelling  sur- 
rounding the  optic  nerv^e,  like  a  wall  elevated  above  the  surface  of 
the  optic  disc,  and  therefore  due  to  a  thickening  of  the  external 
layers  of  the  retina.  The  same  appearance,  however,  also  occurs 
independent  of  syphilis. 

The  course  of  this  form  of  retinitis  is  quite  varied.  With 
proper  treatment,  the  majority  of  cases  recover  in  from  six  to 
eight  weeks,  but  other  cases  prove  very  obstinate.  Atrophy  of 
the  retina  and  of  the  optic  nerve  may  occur  from  a  slow  thinning 
and  increasing  aniemia  of  the  arteries. 

Von  Graefef  describes  a  recurring  central  retinitis  as  a  peculiar 
and  quite  rare  form.  Its  connection  with  syphilis  was  probable, 
from  the  fact  that  in  the  seven  cases  which  were  observed,  syphilis 
had  formerly  existed. 

The  disease  is  characterized  by  a  sudden  disturbance  of  vision, 
which  at  first  after  a  few  days  disapjicars  spontaneously,  to  return 
again  after  some  weeks  or  months.  The  intervals  are  at  first  free 
from  all  disturbances  of  vision,  but  later  the  attacks  last  longer 
and  vision  is  not  fully  restored  during  the  intervals.  As  a  rule, 
the  disease  appears  to  occur  on  both  sides,  and  may  cause  tempo- 
rary blindness  when  the  attacks  aifect  both  eyes  at  the  same  time. 
The  ophthalmoscopic  examination  shows  as  cause  for  the  dis- 
turbance of  vision  a  delicate  clouding  in  the  region  of  the  macula 

*  Lelirbuch  der  Ophthalmoscopie,  pag.  369. 
f  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  211. 


RETINITIS   ALBUMINURICA.  465 

lutea;  it  is  greatest  at  the  fovea  centralis,  and  from  tliat  point 
diniinishes  gradually  in  all  directions.  The  neighborhood  of  the 
ojjtic  disc  remains  free,  or  at  most  shows  a  slight  clouding  on  the 
outer  side. 

During  the  intervals  which  are  free  from  inflammation  the 
affected  portion  of  the  fundus  in  recent  cases  appears  quite  nor- 
mal ;  later  there  remains  a  slight  gray  clouding  in  the  neighbor- 
hood of  the  fovea  centralis ;  finally,  there  may  be  a  deposit  of 
black  pigment  patches. 

The  treatment  of  syphilitic  retinitis  is  exactly  that  of  secondary 
syphilis  in  general. 

A  very  characteristic  form  of  retinitis  is  that  which  occurs  in 
connection  with  albuminuria.  It  always  affects  both  eyes,  although 
not  always  in  the  same  degree.  The  characteristic  features  of  the 
ophthalmoscopic  image,  aside  from  the  ordinary  signs  of  retinitis, 
such  as  hypersemia  of  the  veins  and  clouding  of  the  optic  disc 
and  surrounding  retina,  are  hemorrhages  and  a  number  of  white, 
bright,  glistening  patches  in  the  fundus. 

The  hemorrhages  generally  appear  in  the  form  of  large  round 
blood-red  patches,  or  they  may  be  striated  if  they  occur  in  the 
thicker  portions  of  the  nerve-fibre  layer  ;  moreover,  they,  like 
other  hemorrhages,  may  break  through  into  the  vitreous  body. 
Only  seldom  are  they  very  copious,  and  still  more  seldom  are  they 
entirely  absent. 

The  bright  spots  occupy  principally  the  posterior  portion  of  the 
retina,  and  extend  forward  scarcely  as  far  as  the  equator.  They 
may  approach  so  near  the  optic  nerve  as  to  touch  its  margin,  but 
generally  there  is  a  slight  "distance  between  it  and  them.  At  a 
later  stage  they  crowd  closer  together,  especially  near  the  optic 
nerve;  they  increase  in  extent,  and  several  of  them  joining 
together  assume  very  irregular  forms,  having  a  white,  fatty  ap- 
pearance, and  running  out  toward  the  periphery,  especially  along 
the  course  of  the  retinal  vessels,  in  ragged  points,  or  ending  in  a 
great  number  of  fine  white  dots.  It  is  only  occasionally  that  these 
white  spots  are  so  large  that  they  surround  the  optic  disc  completely. 

The  immediate  neighborhood  of  the  optic  disc  generally  shows 
a  gray,  red,  uniform  or  finely  striated  opacity,  which  hides  the 
boundary-line  of  the  optic  disc.     The  tissue  of  the  optic  nerve 


466  EETINITIS   ALBUMINURICA. 

itself  appears  somewhat  clouded,  but  it  is  only  exceptionally  that 
the  existence  of  an  actual  neuritis  is  shown  by  an  evident  swelling. 

At  a  later  stage  the  retinal  vessels,  especially  those  near  the 
optic  nerve,  appear  to  be  accompanied  by  white  lines,  which  are 
to  be  referred  to  a  thickening  of  their  adventitial  coats. 

In  this  form  of  retinitis  there  is  relatively  often  seen  the  above 
mentioned  stellate  grouping  of  fine  white  dots  or  lines. 

The  peripheral  portion  of  the  retina  in  front  of  the  equator 
generally  remains  unchanged. 

Choroidal  changes  frequently  occur  simultaneously.  They 
appear  as  brighter  or  darker  patches  in  the  layer  of  pigment 
epithelium.  In  many  cases  slight  diffuse  opacities  of  the  vitreous 
body  are  also  observed. 

Vision  varies  greatly  in  degree.  It  may  be  so  good  that  ordi- 
nary print  can  still  be  read,  or  it  may  have  become  so  diminished 
that  only  fingers  can  be  counted  at  a  sliort  distance.  The  visual 
field  remains  free  except  when  detachment  of  the  retina  has  oc- 
curred, as  it  exceptionally  does  in  the  later  stages.  Retinitis  albu- 
minurica  appears  but  very  seldom  to  lead  to  complete  blindness.* 

Probably  in  a  considerable  number  of  cases  the  retinal  disease 
would  disappear  if  life  were  prolonged.  In  those  cases  in  which 
the  general  condition  allows  of  a  better  prognosis,  as,  for  instance, 
in  albuminuria  following  scarlet  fever,  or  during  pregnancy,  ob- 
servation has  proved  that  the  retinitis  may  disappear  entirely,  or 
nearly  so,  while  at  the  same  time  there  is  an  improvement  in  vision. 
For  instance,  in  a  case  which  occurred  during  confinement,  I  saw 
recovery  from  the  retinal  disease  and  complete  restoration  of 
vision;  both  affections  recurred' at  a  later  confinement,  and  again 
there  was  recovery.  In  the  second  attack  both  eyes  had  at  the 
height  of  the  disease  a  vision  of  only  about  ywif-  -^^^^  months 
later  one  eye  had  a  vision  of  |,  the  other  of  only  about  J,  as  in 
its  macula  lutea  a  dark,  somewhat  prominent  spot  had  remained. 

This  form  of  retinitis  may  be  developed  in  all  cases  in  which 
albuminuria  has  continued  for  some  time.  This  is  most  frequently 
the  case  in  chronic  Bright's  disease  ;  still,  the  existence  of  retinal 


*  Only  two  such  cases  are  known.  Sec  V.  Graefe  (Arch.  f.  Ophth.,  B.  vi.  2, 
pag.  285),  and  Bonders  (Yan  der  Laan,  Over  gezichtsstoornissen  bij  albumi- 
iiiirie,  Utrecht,  1865,  pag.  216). 


EETINITIS   LEUC^.MICA.  467 

disease  has  also  been  demonstrated  in  connection  with  croupous 
nephritis,  with  amyloid  degeneration  of  the  kidneys,  and  in  the 
passive  hypersemia  of  the  kidneys  caused  by  pregnancy.* 

Only  very  few  statements  have  been  made  respecting  the  rela- 
tive frequency  of  its  occurrence  in  Bright's  disease.  Among  41 
patients,  Frerichsf  found  six  with  more  or  less  disturbance  of 
vision.  LebertJ  states  that  in  one-fifth  of  his  cases  there  were 
amblyopic  symptoms.  Both  statements  are  probably  somewhat 
exaggerated,  since  all  the  disturbances  of  vision  there  observed 
ought  not  to  be  attributed  to  retinitis.  Among  157  cases  of 
Bright's  disease,  Wagner§  found  18  in  which  there  were  visible 
changes  in  the  eye,  but  only  10  of  these  cases  could  with  certainty 
be  considered  as  retinitis  albuminurica. 

Retinal  disease  probably  occurs  in  about  six  or  seven  per  cent, 
of  all  cases  of  Bright's  disease.  The  circumstance  that  the  ex- 
istence of  albuminuria  is  frequently  first  discovered  by  an  oph- 
thalmoscopic examination,  would  perhaps  indicate  that  this  retinal 
aifection  is  relatively  most  frequent  in  those  cases  w^iich  run  an 
irregular  course. 

The  treatment  is  directed  toward  the  general  disease.  The 
usual  antiphlogistic  treatment  of  retinitis,  by  bleeding  and  so 
forth,  is  seldom  indicated.  Rest  and  protection  of  the  eyes  from 
all  hurtful  influences  is  therefore  frequently  the  only  additional 
treatment  made  necessary  by  the  retinitis. 

The  ursemic  amaurosis,  which  likewise  occurs  in  Bright's  dis- 
ease, is  of  a  different  nature,  and  has  nothing  in  common  with 
retinitis. 

Leucremia  is  likewise  one  of  the  general  diseases  which  may 
cause  retinitis.  It  is  noticed  that  in  many  cases  of  leucaemia  the 
ophthalmoscopic  picture  of  the  fundus  is  of  a  remarkable  orange- 
yellow  color,||  due  perhaps  to  the  lighter  color  of  the  blood,  caused 
by  the  preponderance  of  the  white  blood-corpuscles.     It  is,  how- 

*  Traube,  Deutsche  Klinik,  1859,  pag.  67. 

f  Die  Brightische  Nierenkrankheit,  pag.  93. 

X  Handbuch  der  practischen  Medicin,  1859,  B.  2,  pag.  608. 

I  Virchow's  Archiv,  1867,  B.  xii. 

II  Liebreieh,  Deutsche  Klinik,  1801,  No.  50;  0.  Becker,  Arch.  f.  Augen- 
und  Ohrenheilk.,  18G9,  B.  i.  pag.  95. 


468  RETINITIS   NYCTALOPICA. 

ever,  noticeable  that  this  orange-yellow  color  of  the  ophthalmo- 
scopic picture  is  wanting  in  other  cases  of  decided  leucaemia,*  and 
that  it  may  even  be  wanting  in  cases  of  decided  retinitis  due  to 
this  disease. t 

The  ophthalmoscopic  signs  of  retinitis  leucseraica  are  opacity 
of  the  retina  about  the  optic  disc,  more  or  less  numerous  hemor- 
rhages, and  small  white  round  spots,  the  largest  of  which  do  not 
equal  the  size  of  the  optic  disc. 

Frequently  hemorrhages  appear  upon  these  spots,  the  largest 
of  them  evidently  forming  a  prominence  above  the  inner  surface 
of  the  retina. 

These  spots  do  not  occur  in  the  neighborhood  of  the  optic  disc 
and  macula  lutea  alone,  but  may  be  found  in  the  more  peripheral 
portions  of  the  fundus.  In  many  cases  white  lines  are  seen  along 
the  course  of  the  retinal  vessels.  Siimisch  observed  simultaneously 
choroidal  hemorrhages.  Leber|  found,  upon  anatomical  exami- 
nation, that  the  white  spots  consisted  simply  of  accumulations  of 
lymph-corpuscles.  He  is  inclined  to  regard  them  as  small  leu- 
cseraic  tumors,  such  as  Virchow  has  pointed  out  in  various  organs, 
and  such  as  Engel-Reimers§  saw  in  the  choroid.  The  white  lines 
along  the  course  of  the  vessels  aj^pear  also  to  be  caused  by  lymph- 
corpuscles. 

Recklinghausen  found  the  bright  spots  in  one  case  to  be  com- 
posed of  thickened  nerve  fibres. 

The  disturbances  of  vision  appear  generally  to  be  very  slight, 
unless  the  macula  lutea  is  considerably  affected  or  a  hemorrhage 
into  the  vitreous  has  occurred.  Siimisch,  in  a  case  which  he  had 
under  observation  for  a  year  and  a  half,  saw  the  hemorrhages  and 
the  white  spots  disappear;  after  4  or  5  months  they  appeared 
anew,  and  later  disappeared  again ;  still,  the  posterior  portion  of 
the  retina  remained  all  the  time  slightly  clouded. 

Under  the  name  of  "retinitis  nyctalopica"  Arlt||  describes  a 
form  of  retinitis  characterized  less  by  the  ophthalmoscopic  appear- 

*  Knapp,  Klin.  Monatsbl.,  18G8,  pag.  355;  O.  Becker,  a.  a.  O.,  pag.  105. 

t  Samisch,  Klin.  Monatsbl.,  1869,  pag.  305. 

X  Klin.  Monatsbl.,  1869,  pag.  312. 

§  Centralblatt  der  nied.  Wissenschaft.,  1868,  pag.  836. 

I)  Bericht  iiber  die  Wiener  Augenklinik,  "VVien,  1867,  pag.  123. 


k 


RETINITIS   OF   THE   MACULA    LUTEA.  469 

ances  than  by  its  clinical  history.  Its  most  prominent  symptoms 
are  the  dazzling  caused  by  full  daylight,  and  diminution  of  vision. 
This  last  symptom  is  observed  when  looking  at  distant  objects, 
which  appear  to  the  patients  as  if  veiled  by  a  light  cloud,  or  as  if 
the  intervening  air  were  in  vibration.  The  diminution  of  vision  is 
generally  not  very  great,  and  the  visual  field  remains  free.  Both 
eyes  are  always  attacked  at  the  same  time,  and  in  the  same  or 
nearly  the  same  degree.  The  ophthalmoscopic  changes  are  said  to 
be  a  slight  uniform  or  perhaps  striated  opacity  of  the  retina  near  the 
optic  disc,  or  extending  outward  toward  the  equator.  The  limits 
of  the  optic  disc  are  more  or  less  indistinct;  its  surface  in  most  cases 
is  decidedly  redder  than  normal,  in  other  cases  it  shows  no  changes. 

Arlt  is  of  the  opinion  that  hyperjemia  and  inflammatory  changes 
exist  at  the  beginning  in  all  cases,  but  that  they  frequently  escape 
observation  because  they  are  so  slight  as  to  be  overlooked  in  the 
examination  in  the  upright  image,  or  because  at  the  time  of  the 
examination  they  have  already  partly  disappeared. 

The  disturbances  of  vision  generally  come  on  suddenly,  and 
either  remain  a  long  time  the  same  or  increase  gradually  to  a 
degree  where  they  may  remain  months  or  years  stationary,  without 
going  on  to  complete  blindness.  Arlt  regards  dazzling  by  bright 
reflected  or  difl:use  sunlight  as  the  principal  cause  of  this  affection. 
The  treatment  requires  rest  for  the  eyes  and  protection  from  the 
light,  the  patient  remaining  in  a  moderately  dark  room  or  using 
blue  or  smoked-gray  spectacles.  Simultaneously,  mild,  cooling 
cathartics,  moderate  bleeding,  and,  as  a  special  treatment,  a  metliod- 
ical  use  of  mercury,  either  by  inunction  or  in  pills  of  corrosive 
sublimate  in  increasing  doses,  should  be  resorted  to. 

It  may  finally  be  mentioned  that  in  many  cases  besides  those 
of  the  above  named  syphilitic  form  the  retinitis  is  localized  in  the 
region  of  the  macula  lutea.  The  fovea  centralis  never  participates 
in  this  opacity,  and  for  that  reason  appears  as  a  bright-red  spot, 
whose  boundaries  are  all  the  more  distinct  for  the  reason  that  just 
here  the  white  discoloration  of  the  retina  is  greatest.  Toward  the 
periphery  the  opacity  gradually  disappears,  extending  often  scarcely 
beyond  the  region  of  the  macula  lutea.  It  may,  however,  reach 
the  margin  of  the  optic  disc,  or  at  certain  points  extend  still  far- 
ther outward.      Hemorrhages  often  exist  at  the  margins  of  these 


470  EETINITIS. 

opacities.  In  the  course  of  a  few  weeks  the  opacity  begins  to 
clear  up  at  its  periphery,  and  may  finally  absolutely  disappear; 
meanwhile  a  whitish  discoloration  of  the  optic  disc  develops. 

In  many  cases,  as  the  retina  clears  up,  noticeable  clianges  be- 
come apparent  in  the  pigment  epithelium  layer  of  the  choroid. 
In  some  of  these  cases  I  have  also  observed  severe  pain  at  the 
beginning  of  the  disease,  so  that  the  entire  process  ought  to  be 
regarded  as  a  choroiditis  with  infiltration  of  the  retina,  while  those 
cases  which  recover  without  leaving  any  choroidal  changes  should 
be  regarded  simply  as  a  retinitis  of  the  macula  lutea.  Another 
ophthalmoscopic  change,  however,  frequently  remains  after  these 
cases,  namely,  a  whitish  discoloration  of  the  of)tic  disc,  with  con- 
traction of  the  retinal  arteries. 

The  disturbances  of  vision  are  always  very  great,  the  subjective 
symptom  being  that  of  a  dark  spot  covering  the  object  fixed.  It 
can  often  be  proved  experimentally  by  the  ophthalmoscope,  or 
by  some  other  method,  that  there  is  no  sensation  of  light  in  the 
macula  lutea.  Eccentric  vision,  however,  remains  unaffected. 
With  the  disappearance  of  the  opacity,  vision  may  likewise  im- 
prove, but  generally  remains  somewhat  defective. 

The  anatomical  changes  in  retinitis  are  best  known  in  that 
form  caused  by  Bright's  disease,  for  the  reason  that,  in  consequence 
of  the  fatal  result  of  the  general  disease,  it  is  just  such  cases  in 
which  the  opportunity  for  examination  is  most  frequent.  It  ap- 
pears, however,  that  this  form  of  retinitis  presents  no  anatomical 
peculiarities  specially  differing  from  the  others.  * 

We  will  here  consider  the  anatomical  changes  specially  as  ac- 
counting for  the  ophthalmoscopic  appearances  and  the  functional 
disturbances. 

The  opacity  of  the  retina  is  to  be  explained  by  quite  a  number 
of  afiatoniical  changes.  And  first,  it  is  here  to  be  mentioned  that 
in  many  cases  of  retinitis  albuminurica  Virchow*  and  H.  Miillerf 
found  a  very  unusual  toughness  of  the  retina,  and  Miiller  thought 
it  probable  that  this  might  in  some  way  be  a  cause  of  the  diffuse 
opacity. 

*  Verhandluiigen  der  phys.  med.  Gesellsch.  zu  Wiirzburg,  B.  ix.  pag.  35. 
f  Wurzburger  med.  Zeitschrift,  i.  18G0,  pag.  50. 


ANATOMICAL   CHANGES.  471 

The  more  dense  opacities  may  depend  upon  inflammatory  infil- 
tration of  the  retina.  Coagula  which  are  found  in  the  retina, 
partly  as  compact,  tough  masses,  and  partly  in  filn-ous  form,  may 
to  some  extent  have  been  present  duting  life,  but,  for  the  most 
part,  tliese  appearances  seem  to  be  due  to  the  action  of  the  harden- 
ing fluid  upon  the  coagulable  substances. 

An  important  part,  too,  is  played  by  the  hypertrophy  of  the 
connective  tissue,  which  may  occur  in  all  the  layers  of  the  retina. 
The  process  is  one  of  tliickening,  with  proliferation,  hypertrophy, 
and  often  fatty  degeneration  of  the  normal  connective-tissue  nuclei 
and  cells.  The  nuclei  of  the  radial  fibres,  too,  are  found  enlarged 
and  proliferated  in  cases  of  acute  retinitis. 

In  the  granular  layer  of  the  retina  the  hypertrophy  of  the  con- 
nective tissue  causes  an  elongation  of  the  radial  fibres  and  an 
unevenness  in  the  surface  of  this  layer.  But  this  change  is  not 
uniform  throughout  the  entire  retina,  some  small  portions  remain- 
ing unchanged,  or  nearly  so.  The  external  surface  of  the  retina 
is  thus  made  uneven.  A  perpendicular  section  is  seen  to  be  full 
of  furrows,  all  lined  by  the  delicate  merabrana  limitans  externa, 
and  filled  with  broken-down  rods  or  choroidal  epithelium. 

This  growth  of  the  outer  ends  of  the  radial  fibres  may  cause 
disturbances  of  vision  by  destruction  of  the  layer  of  the  rods  and 
cones,  and  may  also  leave  visible  choroidal  changes. 

The  bright  spots  which  are  seen  in  retinitis  are  mostly  due  to 
two  changes,  namely,  a  fatty  degeneration  of  the  retina  and  a 
peculiar  metamorphosis  of  the  nerve  fibres. 

Fatty  degeneration  is  most  frequent  in  retinitis  albuminurica, 
and  principally  in  the  external  granular  layer,  but  may  occur  in 
all  the  layers.  It  also  occurs  in  other  forms  of  retinitis,  and 
has,  for  instance,  been  several  times  demonstrated  anatomically  in 
neuro-retinitis  caused  by  cerebral  disease.* 

In  the  ophthalmoscopic  image  the  fatty  degenerations  gener- 
ally appear  as  round  spots,  seldom  as  striated  opacities.  Still,  in 
one  case  of  Bright's  disease  Virchowf  found  a  radiating,  striated 


*  Nagel,  Arch.  f.  Ophth.,  B.  vi.  1,  pag.  196;  Kosler,  Twee  gevallen  van 
tumor  cerebri,  Utreclit,  1865,  pag.  13;  H.  Schmidt  und  Wegner,  Arch.  f. 
Ophth.,  B.  XV.  3,  pag.  253. 

t  Verhandl.  der  phys.  med.  Gesellschaft  zu  Wiirzburg,  B.  x.  pug.  36. 


472  RETINITIS. 

opacity  of  the  retina,  caused  by  a  fatty  degeneration  of  the  inner 
ends  of  the  radial  fibres,  close  to  the  membrana  limitans  interna. 
In  a  case  which  I  examined,*  a  stiffness  of  the  retina  was  caused 
by  a  sclerotic  thickening  of  the  ends  of  these  fibres. 

Some  of  the  most  striking  changes  seen  in  retinitis  are  found  in 
the  nerve  elements  of  the  internal  layers.  Heyman  and  Zenkerf 
and  Virchow;}:  observed  this  degeneration  in  Bright's  disease,  first 
in  the  inner  layers  of  the  retina,  and  referred  it  to  an  affection  of 
the  ganglion  cells,  which  Virchow  designated  as  sclerosis.  The 
resemblance  of  these  sclerosed  elements  to  ganglion  cells  is  very 
great ;  but  H.  Muller§  showed  that  in  the  case  examined  by  him 
these  form  elements  were  the  result  of  changes  in  the  nerve  fibres. 

The  sclerotic  thickening  affected  princi}3ally  the  varicosities  of 
the  nerve  fibres.  Several  successive  varicosities  are  seen  to  increase 
in  thickness,  till  suddenly  one  such  swelling  attains  an  enormous 
size.  The  fibre  in  the  immediate  neighborhood  is  also  thickened, 
but  soon  returns  to  its  normal  size.  The  individual  swellings 
appear  as  sharply  defined,  roundish,  club-  or  retort-shaped  bodies, 
are  generally  finely  granulated,  and  not  infrequently  show  a 
nucleus  in  their  interior. 

In  spite  of  the  remarkable  similarity  of  these  bodies  to  ganglion 
cells,  it  seemed,  in  a  case  which  I  examined,  that  Midler's  view 
as  to  their  nature  is  the  correct  one,  from  the  fact  that  by  far  the 
most  of  them  showed  no  signs  of  a  nucleus,  and,  moreover,  the 
same  chanses  in  less  advanced  stag-es  were  visible  on  the  nerve 
fibres. 

In  another  form  of  sclerotic  degeneration  of  the  nerve  fibres 
there  is  a  uniform  thickening  along  a  considerable  extent  of  the 
fibres,  but  no  club-shaped  swellings.  The  nerve  fibres  increase 
gradually  in  thickness,  retain  for  a  shorter  or  longer  distance 
their  abnormal  size  with  but  slight  variations,  and  generally  pre- 
sent a  peculiar  opalescent  appearance. 

Lastly,  ca.ses  occur  in  which  this  opalescence  is  wanting.  The 
fibres  then  appear  simply  hypertrophied,  usually  presenting  in 


*  Arch.f.  Ophth.,  B.  vi.  2,  pag.  290. 
t  Ibid.,  B.  ii.  2,  pag.  142. 
J  Arch.  f.  path.  Anat.,  B.  x.  pag.  17( 
§  Arch.  f.  Ophth.,  B.  iv.  2,  pag.  41. 


ANATOMICAL   CHANGES.  473 

their  course  or  in  their  varicosities  dark  points,  which  probably 
are  fat  drops. 

As  a  rule,  the  sclerosed  nerve  fibres  lie  in  groups,  causing  swell- 
ings, which  protrude  inward  above  the  surface  of  the  retina,  and 
also  encroach  on  the  external  layers. 

It  may,  however,  happen,  and  that  principally  at  the  intraocular 
extremity  of  the  optic  nerve,  that  the  hypertrophy  of  the  nerv^e 
fibres  does  not  occur  at  circumscribed  points,  but  more  diffusely 
over  the  surface  of  the  disc  and  the  adjoining  retina,  thereby 
contributing  to  a  swelling  of  the  disc  and  retina. 

The  sclerosed  portions  appear  ophthalmoscopically  as  bright, 
glistening,  white  spots.  It  is  doubtful  whether  in  all  cases  they 
can  be  distinguished  from  circumscribed  fatty  degeneration ;  still, 
small  bright  spots  lying  in  front  of  the  retinal  vessels — that  is, 
belonging  to  the  inner  retinal  layers — may  with  great  probability 
be  regarded  as  composed  of  sclerosed  fibres.  It  is  also  of  diag- 
nostic importance  that  hemorrhages  frequently  occur  among  these 
degenerated,  sclerotic  nerve  elements. 

Such  spots  are  as  likely  to  occur  in  the  optic  disc  as  in  the 
retina. 

These  peculiar  changes  were  first  observed  in  retinitis  albu- 
minurica,  but  later  investigations  have  shown  that  they  may  be 
absent  in  this  and  present  in  other  forms  of  retinitis. 

Wounds  of  the  retina  may  cause  a  varicose  hypertrophy  of  its 
nerve  fibres.* 

Virchowf  was  also  the  first  to  observe  in  Bright's  disease  a 
sclerotic  infiltration  of  the  w^alls  of  the  retinal  vessels.  They  are 
also  frequently  found  to  be  undergoing  fatty  degeneration. 

Choroidal  changes  occur  in  connection  with  retinitis.  Virchow^; 
found  in  Bright's  disease  round  masses  of  sclerosed  substance  in 
the  choroid,  corresponding  to  the  degenerated  portions  of  the 
retina.  H.  Muller§  demonstrated  a  thickening  of  the  walls  of 
the  vessels  by  a  homogeneous  strongly  refracting  substance.  In 
some  cases  which  I  examined  there  was  likewise  sclerosis  of  various 

*  Koth,  Beitrage  zur  varicosen  Hypertrophie  der  Nervenfasern,  Virchow's 
Arch.,  B.  Iv. 

f  Arch.  f.  path.  Anat.,  B.  x.  pag.  178. 

X  Verhandlungen  der  physio.  Gesellschaft  zu  "Wiirzburg,  B.  x.  pag.  36. 
§  Wiirzburger  med.  Zeitschrift,  B.  i. 

31 


474  RETINITIS. 

vascular  regions  in  certain  parts  of  the  choroid.  The  pigment 
epithelium  covering  these  places  had  generally  lost  its  color.  I 
could  not  satisfy  myself  that  there  was  any  direct  relation  with 
the  retinal  changes.  This  co-affection  of  the  choroid  has  been 
shown  to  be  most  frequent  in  Bright's  disease.  Schmidt  and 
Wegner,*  however,  observed  sclerosis  of  the  choroidal  vessels  in 
connection  with  neuro-retinitis. 

In  one, case  of  retinitis  album inurica,  H.  Miillerf  demonstrated 
a  peculiar  embolism  of  the  fine  ciliary  arteries.  A  hypertrophy 
and  fatty  degeneration  of  the  lining  epithelium  of  these  arteries 
was  the  cause  of  the  formation  of  emboli  composed  of  detached 
and  degenerated  epithelium,  young  cells,  and  free  flit,  which  were 
found  here  and  there  wedged  in  the  smaller  branches. 

In  the  vitreous  were  found  opacities  consisting  of  a  countless 
number  of  interwoven  threads.  Possibly  there  may  be  often  a 
peculiar  post-mortem  form  of  fibrin  coagulation;  still,  in  the  cases 
w^hich  I  examined,  a  diffuse  vitreous  opacity  had  been  already 
observed  ophthalraoscopically.| 

It  has  been  already  mentioned  that  a  proliferation  of  the  con- 
nective tissue  of  the  adventitial  coat  of  the  retinal  vessels  often 
occurs,  and  that  it  is  recognized  ophthalmoscopically  by  bright 
stripes  accompanying  the  vessels. 

In  rare  cases  this  disease  extends  over  a  large  part  of  the  retina, 
and  is  of  so  high  a  degree  that  the  vessels  appear  transformed 
into  white  strings,  which  still  often  betray  the  blood  within  them 
by  a  thin  red  line.§ 

Iwanoff,||  who  found  a  similar  condition  upon  anatomical  exam- 
ination, designated  the  disease  as  "perivascular  neuritis."  In  an 
eye  blinded  by  a  severe  injury,  besides  swelling  and  oedematous 
saturation  of  the  intraocular  extremity  of  the  optic  nerve  and  the 
retina,  there  was  found  a  very  great  thickening  of  the  retinal 
vessels,  which  appeared  as  white,  slightly  prominent  stripes. 

The  thickening  was  caused  by  a  change  in  the  adventitial  coat, 

*  L.  c,  pag.  2f)3. 

f  Wiirzburger  med.  Zeitschrift,  B.  i. 
X  Arch.  f.  Ophth.,  B.  vi.  3,  pag.  279  and  290. 

^  Nagel,  Klin.   Monatsbl.  f.  Augenheilk.,  1864,  pag.  394;  E.  v.  Jaeger, 
Ophtlialmoscopischer  Handatlas,  Fig.  50,  51,  und  75. 
II  Klin.  Monatsbl.  f.  Augenheilk.,  1865,  pag.  328. 


NEURO-EETINITIS.  475 

wliich  generally  was  more  developed  on  the  arteries  than  on  the 
veins.  These  changes  extended  into  the  optic  nerve  itself,  and 
consisted  essentially  in  a  very  considerable  increase  in  the  con- 
nective-tissue nuclei.  The  ganglion  cells  and  nerve  fibres  of  the 
retina  were  well  preserved. 

N  EUKO-RETINITIS. 

l!^euro-retinitis  or  neuritis  is  the  name  given  to  those  cases  in 
which  the  ophthalmoscopic  changes  are  confined  to  the  optic  disc 
or  its  immediate  neighborhood.  The  principal  features  in  the 
ophthalmoscopic  image  are  hyperemia,  clouding,  and  swelling  of 
the  tissues. 

The  hypersemia  is  most  a[)parent  in  the  retinal  veins,  which  are 
greatly  dilated  and  very  sinuous.  The  arteries  are  generally  some- 
what contracted,  in  some  cases  remarkably  so.  Spontaneous  arte- 
rial pulsation  occurs  in  only  very  rare  cases.* 

In  consequence  of  the  dilatation  of  the  numerous  small  vessels 
of  the  optic  nerve,  the  disc  is  noticeably  reddened,  the  color  being 
sometimes  modified  by  a  bluish  tinge,  the  result  being  a  lilac  shade, 
which  in  such  cases  generally  extends  somewhat  upon  the  retina. 

The  clouding  of  the  nerve  and  neighboring  retinal  tissue  causes 
the  deeper  parts,  such  as  the  lamina  cribrosa,  the  boundary-line  of 
the  optic  disc,  and  some  of  the  deeper  curves  of  the  retinal  vessels, 
to  be  obscured  or  absolutely  hidden. 

The  swelling  of  the  optic  nerve  may  be  relatively  less  than 
that  of  the  retina,  which  consequently  rises  up  about  the  disc  like 
a  wall.  But,  as  a  rule,  the  nerve  is  at  least  as  much  swollen  as 
the  retina,  often,  indeed,  more,  so  that  its  intraocular  extremity 
rises  above  the  general  surface  of  the  retina. 

The  swelling  of  the  optic  nerve  is  recognized  ophthalmoscopic- 
ally  in  the  same  manner  as  are  other  variations  of  level  in  the 
fundus  of  the  eye.  It  is  most  easily  seen  by  observing  the  course 
of  the  retinal  vessels,  which  rise  up  over  the  prominence  and  then 
sink  to  the  level  of  the  retina.  Those  portions  of  the  vessels 
which  are  driven  forward  are  distinctly  visible  in  the  upright 
image;  they  present  a  greater  parallax  than  the  neighboring 
portions  lying  in  the  plane  of  the  retina. 


*  Von  Graefe  saw  it  in  three  cases,  Arch.  f.  Ophth.,  B.  xii.  3,  pag.  131. 


476  NEURO-RETINITIS. 

The  retina,  so  far  as  it  is  involved  in  the  process,  presents  the 
appearances  described  under  the  head  of  retinitis.  But  in  many 
cases  the  opacity  is  but  slight,  and  is  confined  to  the  neighbor- 
hood of  the  optic  disc,  or  extends  somewhat  farther  along  the 
course  of  the  vessels.  The  sinuosities  of  the  retinal  veins  fre- 
quently extend  far  into  the  transparent  portion  of  the  retina,  and 
when  their  curves  are  in  a  plane  perpendicular  to  that  of  the 
retina,  it  is  possible  to  recognize  an  oedema  of  that  membrane. 

Striated  hemorrhages  in  the  neighborhood  of  the  optic  disc,  or 
circular  ones  in  the  more  peripheral  portions,  are  sometimes  seen. 
White  spots  appear  partly  in  consequence  of  circumscribed  scle- 
rotic degeneration  of  the  retinal  nerve  fibres  or  of  the  optic  nerve 
itself,  partly  as  the  expression  of  a  fatty  degeneration.  There  is 
often  also  a  peculiar  stellate  punctation  about  the  macula  lutea. 

In  the  course  of  time  the  swelling  of  the  optic  nerve  diminishes, 
the  redness  disappears,  but  the  disc  remains  clouded  with  a  gray 
or  whitish  discoloration.  The  same  is  true  to  a  less  degree  of  the 
neighboring  parts  of  the  retina.  In  some  cases  I  have  noticed  at 
this  stage  a  remarkable  sinuosity  of  the  retinal  veins  on  the  surface 
and  in  the  neighborhood  of  the  optic  nerve.  Frequently  after  the 
subsidence  of  the  swelling  of  the  nerve  and  the  clearing  up  of  the 
retina,  slight  choroidal  changes  are  seen  about  the  optic  nerve, 
which  are  to  be  accounted  for  by  the  spreading  of  its  intraocular 
extremity  and  the  growth  of  the  outer  retinal  layers,  processes 
yet  to  be  explained. 

Vision  is  generally  much  interfered  with,  and  there  are  usually 
noticeable  defects  in  the  visual  field.  Still,  just  as  in  retinitis, 
and  for  the  same  reasons,  there  is  no  correspondence  between  the 
ophthalmoscopic  appearances  and  the  degree  of  vision. 

Frequently  during  the  course  of  the  disease  very  considerable 
changes  in  the  degree  of  vision  occur  without  any  corresponding 
ophthalmoscopic  changes;  or,  on  the  other  hand,  during  a  long 
persistence  of  the  disease,  very  great  ophthalmoscopic  changes 
may  take  place  with  but  slight  additional  loss  of  vision. 

It  is  a  remarkable  phenomenon  that  in  such  cases,  when  good 
vision  has  been  retained,  there  may  occur  a  sudden  transitory 
darkening  of  the  entire  visual  field. 

Loss  of  vision  generally  follows  gradually,  but  in  some  cases 
comes  on  with  surprising  rapidity,  so  that,  vision  being  good, 


NEURO-EETINITIS.  477 

complete  blindnass  may  occur  in  the  course  of  a  few  hours.  (Neu- 
ritis fulminans,  Von  Graefe.) 

Neuritis  may  occur  as  an  independent  form  of  disease.  Cases 
occur  in  which  no  other  disease  can  be  regarded  as  the  exciting 
cause,  and  in  which  indeed  no  cause  whatever  can  be  discovered. 
Contusions  of  the  eyeball  or  of  the  orbital  walls  are  seldom  to  be 
regarded  as  the  exciting  cause.  Many  cases  depend  upon  consti- 
tutional causes, — such  as  disturbances  of  the  circulation  in  distant 
organs,  anomalies  of  menstruation,  etc.  Syphilis  and  lead  poisoning 
are  also  named  as  causes. 

In  another  class  of  cases  the  direct  effect  of  hurtful  influences 
upon  the  orbital  or  intracranial  course  of  the  nerve  is  evident. 
The  growth  of  tumors  or  inflammatory  processes  in  the  orbit  as 
causes  of  neuritis  have  already  been  mentioned  on  pages  193  and 
194.  Such  causes  may  remain  localized  in  the  depth  of  the  orbit, 
and  their  existence  be  betrayed  by  disturbances  of  vision  and 
subsequent  atrophic  degeneration,  or  they  may  extend  to  the  intra- 
ocular extremity  of  the  optic  nerve. 

Finally,  various  intracranial  diseases,  such  as  meningitis,  in- 
flammatory softening,  tumors  of  the  brain,  etc.,  may  be  compli- 
cated with  neuro-retinitis.  Experience,  however,  is  more  and 
more  against  the  idea  that  the  nature  of  the  intracranial  disease, 
or  its  connection  M'ith  the  neuro-retinitis,  can  be  determined  by 
any  peculiarities  in  the  ophthalmoscopic  appearances. 

In  this  matter  the  occurrence  of  neuro-retinitis  in  connection 
with  brain  tumors  has  played  an  important  part.  A  very  exact 
analysis  of  cases  of  brain  tumor  complicated  with  retinal  disease, 
made  by  Tiirck*  in  1853,  developed  the  view  that  an  increase  of 
intracranial  pressure  rendered  difficult  the  emptying  of  the  oph- 
thalmic vein  into  the  cavernous  sinus,  and  that  thus  disturbances 
of  circulation  were  caused  which  extended  to  the  retina.  In  1860, 
Von  Graefef  sought  by  this  same  theory  to  explain  the  fact,  which 

*  Zeitschrift  der  Gresellschaft  der  Aerzte  zii  Wien,  pag.  218.  Tiirck  found 
no  other  changes  than  retinal  ecchymoses,  which  is  accounted  for  bj'  the  fact 
that  the  retinas  were  not  examined  till  the  fifth  day  after  death. 

f  Arch.  f.  Ophth.,  B.  vii.  2,  pag.  58;  Comp.  Annuske,  Arch.  f.  Ophth.,  B. 
xix.  3,  pag.  165;  Reich,  Klin.  Monatsbl.  f.  Augenheilk,,  1874,  pag.  27-1; 
Heinzel,  Tiber  den  diagnostischen  Werth  des  Augenspiegelbefundes  bei  intra- 
craniellen  Erkrankungen  der  Kinder,  Jalirbuch  fiir  Kinderheilkunde,  1875, 
B.  viii.  3,  pag.  331. 


478  NEURO-HETINITIS. 

his  observations  render  undoubted,  that  there  occurs  in  connection 
with  brain  tumors  a  characteristic  swelling  of  the  nerve,  which 
since  that  time  has  generally  been  called  ''Stauungspapille."* 
The  peculiarity  of  the  condition  consists  in  a  considerable  and 
often  irregular  swelling  and  redness  of  the  optic  nerve,  in  conse- 
quence of  the  dilatation  of  the  delicate  vessels  which  ramify  in 
its  intraocular  extremity.  The  veins  of  the  retina  are  likewise 
dilated  and  abnormally  curved,  while  the  contents  of  the  arteries 
are  diminished.  If  the  condition  be  due  to  cerebral  causes,  both 
eyes  are  always  affected. 

Under  such  circumstances,  vision  is  generally  greatly  diminished ; 
still,  several  cases  of  this  form  of  neuritis  have  been  observed  in 
which  good  vision  was  retained.  In  one  case,  for  instance,  in 
which  the  other  symptoms  Indicated  the  existence  of  a  cerebral 
tumor,  I  found  in  one  eye  a  liigh  degree  of  amblyopia,  with  a 
large  defect  in  the  visual  field,  and  in  the  other  perfect  vision  and 
a  free  visual  field.  Still,  the  ophthalmoscopic  appearances  in  both 
eyes  were  the  same,  except  that  the  optic  disc  of  the  poorer  eye  was 
not  so  red  and  was  of  a  brighter  gray  than  the  other.  In  another 
case,  in  which  besides  decided  "  Stauungspapille"  there  were  cor- 
neal opacities,  vision  was  much  better  than  was  to  be  expected 
from  the  optical  relations.  Unfortunately,  neither  case  remained 
long  under  observation. 

Blessigt  reports  similar  histories.  Mauthner|  publishes  a  ease 
in  which  there  was  normal  vision  with  decided  neuritis.  It  pos- 
sesses special  interest  from  the  fact  that  the  report  includes  the 
results  of  the  anatomical  examination  of  the  optic  nerve.  This 
case  will  be  again  alluded  to. 

Cases  of  neuritis  in  which  there  is  considerable  swelling  of  the 
intraocular  extremity  of  the  optic  nerve,  sinuosity  of  the  retinal 
veins,  but  no  extensive  opacity  of  the  retina,  and  which,  therefore, 
may  be  described  as  "Stauungspapille,"  occur  as  an  independent 
disease,  and  under  circumstances  which  furnish  no  grounds  for 
suspecting  the  co-existence  of  an  intracranial  disease. 

It  cannot  be  denied  that  the  hyperaemia  of  the  optic  nerve  and 

*  "  Choked  disc"  is  the  corresponding  English  expression. — Translnto?- . 

f  Petersburger  med.  Zeitschr.,  1866. 

j  Lchrbuch  der  Ophthalmoscopie,  pag.  293. 


NEURO-RETINITIS.  479 

retina  which  characterized  the  "Stauungspapille"  depends  upon  a 
stasis  of  blood;  but  what  causes  this  stasis?  A  swelling  of  the 
nerve  itself,  especially  if  participated  in  by  the  lamina  eribrosa, 
would  be  sufficient  cause  for  such  a  stasis.  It  is  doubtful  whether 
a  deeper-lying  obstruction  to  circulation  within  the  cranial  cavity 
plays  any  important  part.     It  is  denied  on  anatomical  grounds. 

Sesemann,*  basing  his  views  upon  very  careful  studies  of  the 
anatomy  of  the  orbital  veins,  opposes  the  theory  that  a  stasis  can 
be  caused  in  the  ophthalmic  vein  by  a  simple  increase  of  intracra- 
nial pressure,  and  sets  forth  the  anatomical  relations  as  follows: 

The  vena  centralis  retinae  emerges  from  the  optic  nerve  at  about 
its  middle,  runs  for  a  short  distance  on  its  outer  side,  then  perforates 
the  external  sheath  of  the  nerve,  and  finally  empties  into  the 
cavernous  sinus  or  into  the  ophthalmic  vein. 

In  most  cases,  where  the  vena  centralis  empties  into  the  cavern- 
ous sinus,  and  this  is  the  most  frequent  arrangement,  it  anas- 
tomoses freely  with  the  vena  ophthalmica  superior,  so  freely, 
indeed,  that  it  is  doubtful  in  some  cases  if  it  should  not  rather  be 
said  to  empty  into  this  vein.  Zinn  describes  a  case  in  which  the 
vena  centralis  emptied  only  into  the  vena  ophthalmica.  Seseraann 
observed  a  simple  discharge  into  the  vena  ophth.  inf. 

Finally,  it  sometimes  happens  that  the  optic-nerve  sheath  is 
surrounded  by  a  delicate  venous  plexus,  into  which  empty  the 
vena  centralis  and  some  small  veins  from  the  substance  of  the 
nerve.  The  blood  from  this  plexus  is  conducted  by  a  number  of 
small  veins,  partly  into  the  vena  ophthalmica  sup.,  partly  into 
the  inferior,  and  partly,  also,  into  the  cavernous  sinus.  If  the 
vena  centralis  retinae  be  connected  with  the  vena  ophthalmica,  it 
becomes  thereby  wholly  independent  of  the  cavernous  sinus,  for 
the  vena  ophthalmica  sup.  is  always  connected  by  numerous  anas- 
tomoses with  the  vena  facialis  and  the  vena  ophthalmica  inf.,  and 
this  last  communicates  again  with  the  vena  facialis  anterior  and 
with  the  pterygoid  plexus,  so  that  the  return  of  the  blood  is  amply 
provided  for. 

Aside,  however,  from  these  anastomoses,  Sesemann  explains  it 
as  indifferent  whether  the  vena  cent,  retinae  empties  into  the  vena 


*  Du  Bois-Eeymond's  und  Reichert's  Arch,  fiir  Anat.  und  Physiol.,  1869,, 
No.  2. 


480  NEUEO-RETINITIS. 

ophthalmica  or  into  the  sinus,  since  the  two  last  are  continuous  the 
one  with  the  other,  and  there  can  be  no  obstruction  to  the  return 
of  the  blood  so  long  as  the  way  through  the  facialis  is  free. 
Sesemann  regarded  the  vena  ophthalmica  as  a  waste  weir,  a  so- 
called  emissarium  Santorini  for  the  cavernous  sinus.  If  from  any 
cause  the  pressure  in  the  sinus  increase,  the  vena  ophthalmica 
empties  not  only  its  contents  into  the  facialis,  but  conducts  into  it 
also  blood  from  the  sinus,  and  it  is  the  better  adapted  to  play  this 
part  for  the  reason  that  throughout  its  whole  course  it  possesses  no 
valves.  Finally,  a  compression  of  the  cavernous  sinus  by  a  simple 
increase  of  the  intracranial  pressure  is  not  so  easy  as  one  might 
think.  In  making  injections,  we  have  often  tried  to  compress  the 
cavernous  sinus  in  order  to  prevent  the  escape  of  the  mass  through 
the  sigmoid  sinus,  but  have  never  succeeded  in  doing  it. 

On  pathological  grounds,  too,  the  undoubted  connection  between 
cerebral  tumors  and  neuritis  cannot  be  regarded  as  a  simple  me- 
chanical consequence  of  the  increase  of  intracranial  pressure. 

It  is  remarkable  that  with  "  Stauungspapille"  the  stasis  takes 
place  only  in  the  vena  centralis  retime,  and  not  in  the  other 
branches  of  the  vena  ophthalmica.  Moreover,  venous  congestion 
of  the  retina  is  wanting  in  very  many  cases  where  there  is  un- 
doubtedly increase  of  intracranial  pressure,  and  it  exists  in  many 
other  cases  without  causing  "  Stauungspapille." 

It  is  regarded  as  undoubted  that  in  general  a  connection  exists 
between  "  Stauungspapille"  and  cerebral  tumors,  but  this  peculiar 
form  of  neuritis  may  occur  independent  of  such  tumors  in  conse- 
quence of  orbital  or  intracranial  processes,  and  furthermore  it  may 
be  absent  in  spite  of  the  existence  of  cerebral  tumors.  Cerebral 
tumors  may  even  cause  blindness  without  "  Stauungspapille," 
partly  by  a  form  of  neuritis  which  runs  its  course  without  any 
marked  swelling  of  the  optic  disc,  partly  by  atrophy  of  the  optic 
nerve. 

Cerebral  tumors  may  cause  a  compression  of  the  optic  nerve. 
Ludwig  Tiirck*  has  shown  that  hydrocephalus  ventriculorum  due 
to  tumor  or  any  other  cause  may  produce  blindness  by  the  press- 
ure of  the  floor  of  the  third  ventricle  upon  the  chiasm. 

In  such  cases  a  cyst-like  distention  of  the  tuber  cinereum  is 

*  Zeitschrift  der  Gesellschaft  der  Aerzte  zu  Wien,  1852,  B.  ii.  pag.  299. 


I 


I 


NEURO-EETINITIS.  481 

found  at  the  base  of  the  brain  ;  the  inner  surfaces  of  the  optic 
thalami  are  more  widely  separated,  and  the  crura  cerebri  more 
divergent,  than  in  the  normal  state.  The  optic  tracts  crossing  the 
crura  are  thus  stretched  and  the  chiasm  somewhat  flattened.  In 
three  such  cases  of  very  decided  hydrocephalus,  in  consequence  of 
cancer  of  the  cerebellum,  and  in  which  death  ensued  in  from  seven 
to  nine  months  after  the  appearance  of  amblyopia,  which  increased 
to  complete  amaurosis,  Tiirck  found  in  the  chiasm  a  great  number 
of  nucleated  cells  and  fat  globules  extending  some  distance  into 
the  optic  nerve,  and  in  one  case  even  into  the  retina. 

Much  light  has  been  thrown  upon  the  connection  between  cere- 
bral and  optic-nerve  diseases  by  Schwalbe's*  investigations  with 
reference  to  the  lymph  passages  of  the  eye.  He  has  shown  that 
the  space  between  the  outer  and  the  inner  optic-nerve  sheath  is 
in  direct  communication  with  the  arachnoidal  s])ace,  and  that  an 
injection  will  pass  from  one  into  the  other.  Manzf  has  confirmed 
by  experiment  and  anatomical  examinations  the  view  first  ex- 
pressed by  Schmidt,!  that  pathological  processes  may  be  propa- 
gated through  this  channel.  It  was  found  that  a  pathological 
fluid  effusion  in  the  arachnoidal  space  and  the  signs  of  increased 
intracranial  pressure  were  almost  always  associated  with  an  ac- 
cumulation of  fluid  between  the  optic-nerve  sheaths.  A  per- 
sistence of  this  condition  may  certainly  cause  an  oedema  of  the 
inner  nerve  sheath  and  of  the  connective-tissue  processes  which 
it  sends  into  the  optic  nerve.  These  processes  are  particularly 
numerous  at  the  place  where  the  nerve  enters  the  eyeball.  This 
oedema  will  cause  a  swelling  of  the  optic  disc,  which  may  be  of 
different  degrees  in  its  central  and  peripheral  parts,  or  may  vary 
in  its  different  sectors.  In  the  lamina  cribrosa,  however,  where 
the  optic  nerve  is  surrounded  by  the  sclera,  the  swelling  of  the 
nerve  compresses  its  vessels,  affecting  principally  the  venous  cur- 
rent. The  theory  that  the  "  Stauungspapille"  is  caused  by  the 
pressure  of  the  fluid  collected  in  the  intravaginal  space,  has  little 
in  its  favor.     In  the  first  place,  this  pressure  must  be  so  great  that 


*  M.  Schultze's  Arch.,  B.  vi.,  1870,  pag.  1. 

f  Arch.  f.  Ophth.,  B.  xvi.  1,  pag.  265,  und  Deutsches  Arch.  f.  klin.  Medicin, 
B.  ix.  pag.  339. 

X  Arch.  f.  Ophth.,  B.  xv.  2,  pag.  193. 


482  ISCH.15:MIA    RETINiE. 

the  very  distensible  external  sheath  can  no  longer  yield  to  it,  and, 
in  the  next  place,  the  intracranial  pressure  must  be  equally  great, 
otherwise  the  fluid  between  the  sheaths  Avould  be  forced  back  into 
the  arachnoidal  space. 

A  direct  propagation  of  an  inflammatory  process  of  the  me- 
ninges of  the  brain  through  the  foramen  opticum  is  quite  possible. 

Retrobulbar  neuritis  is  a  name  applied  by  Von  Graefe*  to  a 
certain  condition  in  which  sudden  blindness  occurs.  After  various 
constitutional  diseases,  among  which  Von  Graefe  mentions  measles 
and  febrile  gastric  catarrh,  and  sometimes  also  without  any  serious 
disturbances  of  the  general  health,  the  field  of  vision  grows  obscure. 
There  may  or  may  not  be  subjective  light  and  color  symptoms.  In  a 
few  hours  or  days  there  is  absolute  blindness,  generally  in  both  eyes. 
The  pupil  is  usually  widely  dilated,  and  does  not  react  to  light. 

Upon  ophthalmoscopic  examination  decided  though  not  very 
great  changes  are  seen  at  the  optic  disc.  They  are,  moreover,  very 
transitory.  There  is  a  slight  opacity  over  the  disc  and  the  adjoin- 
ing retina,  but  there  is  little  or  no  elevation  of  the  surface.  The 
arteries  are  small,  the  veins  distended  and  sinuous.  These  slight 
ophthalmoscopic  changes  are  entirely  disproportionate  to  the  dis- 
turbances of  vision,  which  sometimes  reach  the  extreme  of  com- 
plete blindness.  These  symptoms  are  due  to  changes  which  escape 
observation. 

There  is  great  probability  of  the  correctness  of  Von  Graefe's 
view,  that  in  such  cases  the  principal  changes  are  in  the  optic 
nerve,  behind  the  eyeball.     The  disease  is  generally  bilateral. 

It  is  quite  probable,  as  Von  Graefe  suspected,  that  certain  cases 
described  as  "ischsemia  retinae"  were  really  cases  of  retrobulbar 
neuritis.  The  three  cases  of  this  kind  which  have  been  describedf 
were  characterized  by  blindness,  which  came  on  rapidly  in  both 
eyes,  but  without  any  important  visible  changes  other  than  a  slight 
contraction  of  the  retinal  arteries.  In  one  of  these  cases  the  veins 
were  greatly  dilated  and  sinuous.  In  the  other  two  there  was  no 
venous  hypersemia. 

*  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  114. 

f  One  by  Alfred  Graefe,  Arch.  f.  Ophth.,  B.  viii.  1,  pag.  1-43  ;  two  by  Roth- 
mund, Klin.  Monatsbl.,  1866,  pag.  106. 


RETROBULBAR    NEURITIS.  483 

In  these  cases  there  was  only  a  pai'tial  obstruction  to  the  normal 
blood  supply,  and  it  is  accordingly  difficult  to  understand  why  the 
function  of  the  retina  should  have  been  so  completely  interfered 
with;  all  the  more  difficult,  too,  from  the  fact  that  Von  Graefe 
found  vision  scarcely  less  than  normal  in  the  extreme  degree  of 
ischtemia  which  exists  in  the  asphyxiated  stage  of  cholera. 

It  has,  however,  been  demonstrated  that  a  bilateral  retrobulbar 
neuritis,  which  in  a  few  hours  may  destroy  the  sensation  of  light, 
does  occur,  and  manifests  itself  by  slight  and  very  transitory 
changes  at  the  intraocular  extremity  of  the  optic  nerve.  It  is  not 
strano-e  that  these  changes  in  the  nerve  or  retina  were  not  observed 
in  the  three  cases  above  referred  to,  for  they  might  either  have 
already  disappeared,  as  two  of  the  cases  were  not  examined  till 
after  tlie  sixth  and  the  other  till  after  the  fourth  day,  or  the 
changes  may  not  have  existed  to  a  perceptible  degree. 

At  all  events,  it  must  be  admitted  as  a  possibility  that  the  cases 
described  as  ischaemia  were  really  cases  of  retrobulbar  neuritis. 
This  may  be  assumed  with  the  greatest  probability  for  the  case  of 
atrophic  degeneration  of  the  optic  nerve,  with  contraction  of  the 
retinal  arteries,  described  by  Heddaeus  as  ischaemia.* 

Besides  these  acute  forms  of  retrobulbar  neuritis,  there  are 
others  which  run  a  chronic  course.  The  intraocular  extremity 
of  the  optic  nerve  appears  clouded,  whitish,  and  often  slightly 
swelled.  The  cloudiness  generally  extends  beyond  the  margin  of 
the  optic  disc,  whose  boundary -line  is  therefore  somewhat  indis- 
tinct. The  retina  remains  unchanged.  The  large  arteries  are 
generally  contracted,  the  veins  are  normal,  or  only  slightly  dilated. 
As  in  all  these  processes,  the  disturbances  of  vision  vary  greatly. 
They  may  be  limited  to  a  moderate  diminution  of  central  vision,  or 
they  may  amount  to  almost  complete  blindness,  with  great  defects 
in  the  visual  field.  This  chronic  form  of  neuritis  leads  to  atrophic 
degeneration  of  the  optic  nerve,  a  subject  yet  to  be  discussed. 

The  prognosis  in  neuro-retinitis  and  neuritis  is  generally  unfa- 
vorable. Cases  do  occur  in  which  there  is  recovery  of  vision,  even 
when  there  has  been  complete  blindness;  still,  it  is  impossible  to 
state  the  conditions  under  which  so  favorable  a  result  may  be  hoped 

*  Klin,  Monatsbl.,  1865,  pag.  285. 


484  NEUEITIS. 

for.  It  is  to  be  remembered  that  the  prognosis,  with  reference  to 
the  primary  intracranial  processes,  is  frequently  very  unfavorable. 

There  is,  accordingly,  little  encouragement  for  treatment.  De- 
rivatives, bleeding  from  the  temple  or  behind  the  ear,  setons  in 
the  neck,  etc.,  are  generally  recommended,  so,  too,  the  use  of  mer- 
curials or  iodide  of  potassium,  in  so  far  as  they  are  not  forbidden 
by  special  etiological  indications.  Alfred  Graefe  saw  a  return  of 
vision,  after  iridectomy  in  both  eyes,  in  the  case  described  as 
ischsemia  retinae.  Rothmund,  in  his  two  cases  above  referred  to, 
performed  paracentesis  of  the  anterior  chamber,  with  a  similar 
good  result.  But  the  number  of  these  cases  is  too  small  to  draw 
from  them  any  certain  conclusions  as  to  their  proper  treatment, 
for  in  neuritis,  even  after  protracted  blindness,  a  spontaneous 
restoration  of  vision  has  been  observed. 

The  anatomical  condition  of  the  nerve  trunk  in  neuritis  has 
been  examined  often  enough  to  prove  that  changes  not  visible  by 
the  ophthalmoscope  may  play  an  important  part  in  causing  the 
disturbances  of  vision. 

Tiirck*  observed  inflammatory  processes  in  the  optic  nerves 
and  chiasm  in  various  brain  diseases.  Stellwagf  described  the 
anatomical  changes  in  neuritis,  and  reports  also  some  cases  in 
which  a  dropsical  swelling  of  the  optic  nerve  within  the  cranial 
cavity  was  the  cause  of  blindness. 

Eifusions  between  the  two  optic-nerve  sheaths,  simultaneously 
with  meningitis,  may  be  explained  by  the  anatomical  relations  set 
forth  on  page  481,  but  it  has  also  been  demonstrated  that  an  actual 
propagation  of  an  inflammation  may  take  place  along  the  nerve 
itself. 

Virchow|  observed  in  a  case  of  basilar  meningitis  a  very  marked 
thickening  and  detachment  of  the  neurilemma  along  the  whole 
course  of  the  nerve.  B&sides  this  "  perineuritis,"  he  found  an 
"  interstitial  neuritis,"  likewise,  throughout  the  whole  nerve,  whose 
neurilemma  was  found  fall  of  nuclei  and  young  cells. 


*  Zcitschrift  der  Gesellschaft  der  Aerzte  zu  "VVien,  "B.  v.  2,  pag.  582  ;  B.  viii. 
2,  pag.  299  ;  B.  ix.  2,  pag.  214. 

f  Ophthalmologie,  B.  ii.  pag.  564  und  620. 
X  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  118. 


ANATOMICAL   CHANGES.  485 

Hulke*  reports  a  case  of  "  Stauungspapille"  which  had  devel- 
oped in  connection  witli  extensive  syphilitic  brain  disease.  He 
called  special  attention  to  the  fact  that  there  was  an  evident  swell- 
ing of  both  the  orbital  and  intracranial  portions  of  the  optic  nerve. 
Von  Graefe  believed  that  this  so-called  Neuritis  descendens  could 
be  recognized  by  the  ophthalmoscopic  ap})earances,  w'hich  he  re- 
garded as  consisting  in  moderate  swelling  and  redness  of  the  optic 
disc,  with  extreme  clouding  of  its  tissue,  these  appearances  extend- 
ing somewhat  upon  the  neighboring  retina.  In  "  Stauungspapille" 
the  changes  are  limited  to  the  optic  disc,  the  extraocular  portion 
of  the  nerve  being  unaffected. 

It  has  been  usual  in  the  examination  of  cases  of  neuro-retinitis, 
associated  with  brain  disease,  to  regard  the  optic  nerve  as  un- 
changed when  no  abnormities  can  be  seen  in  it  with  the  naked 
eye.  But  Leberf  has  shown  that  though  the  external  appear- 
ance of  the  nerve  be  normal,  that  is  not  enough  to  exclude 
very  important  pathological  changes.  Among  the  changes  which 
are  to  be  seen  in  such  cases  on  microscopical  examination  are 
interstitial  neuritis  and  perineuritis,  fatty  degeneration  of  the 
nerve  fibres,  an  infiltration  with  nucleated  cells  and  simultaneous 
atrophy  of  the  nerve  fibres.  In  no  case  in  which  neuritis  has 
been  diagnosed  ojihthalmoscopically,  and  in  which  the  macro- 
scopic appearance  of  the  optic-nerve  trunk  is  normal,  are  delicate 
changes  of  some  kind  or  other  wanting. 

The  intraocular  anatomical  appearances  do  not  vary  greatly 
from  those  of  retinitis.  The  swelling  of  the  disc  is  due  mostly 
to  a  hypertrophy  of  the  nerve  fibres,  some  of  which  are  uni- 
formly thickened,  while  others  present  fusiform  or  club-shaped 
swellings.  An  oedematous  saturation  of  the  disc  and  the  develop- 
ment of  numerous  vessels  may  also  contribute  to  the  swelling. 

A  considerable  swelling  may  be  caused  by  a  proliferation  of  the 
connective-tissue  elements.  The  lamina  cribrosa  swells,  is  driven 
forward,  and  projects  above  the  inner  surface  of  the  sclera,  or  its 
tissues  are  so  separated  that  both  its  interior  and  its  exterior  limits 
disappear.  By  this  swelling  and  hypertrophy  of  the  connective- 
tissue  elements  the  intraocular  extremity  of  the  optic  nerve  becomes 

*  Ophth.  Hosp.  Rep.,  1868,  vol.  vi.  pag,  100. 
f  Arch.  f.  Ophth.,  B.  xiv.  2, pag.  333. 


486 


NEURITIS. 


not  only  higher  but  broader,  so  that  it  projects  on  all  sides  beyond 
the  foramen  choroideae. 

Fig.  45  represents  a  considerable  swelling  of  the  intraocular 
extremity  of  the  optic  nerve  and  tlie  lamina  cribrosa  in  a  case  of 
retinitis  caused  "by  Bright's  disease.  The  central  vessels  of  the 
retina,  which  have  been  driven  forAvard  by  the  swelling,  have  by 
their  elastic  resistance  caused  a  depression  in  the  anterior  surface 
of  the  swollen  disc. 

Fig.  45. 


^^^ 


The  lamina  cribrosa,  together  with  the  vessels,  is  driven  for- 
ward and  elevated  above  the  surface  of  the  choroid.  The  con- 
nective-tissue fibres  running  from  the  nerve  into  the  retina  can 
yet  be  recognized.  The  intraocular  extremity  of  the  optic  nerve 
is  greatly  swollen  and  extended  on  all  sides,  not  only  pressing  for- 
ward into  the  vitreous,  but  spreading  also  in  a  lateral  direction. 
The  external  layers  of  the  retina  are  therefore  pushed  aside  as  far 
as  e.  The  separation  between  the  choroid  and  the  retina  which 
appears  in  the  preparation,  is  artificially  produced  ;  but  supposing 
it  not  to  exist,  it  will  be  seen  that  there  must  have  been  during 
life  a  very  considerable  swelling  of  the  optic  disc. 

Silniisch*  gives  a  similar  representation  in  a  case  of  neuro- 
retinitis  caused  by  brain  tumor. 

Most  cases  of  decided  swelling  of  the  optic  disc  present  upon 
anatomical  examination  undoubted  inflammatory  changes.  In  the 
neighboring  retina  there  is  frequently  a  hypertrophic  development 
of  the  connective  tissue  in  all  the  layers,  and  often  the  adventitial 


*  Beitras^e  zur  Anatomie  des  Auges,  1862,  Taf.  iii.  Fig.  2. 


EMBOLISM    OF   THE    CENTRAL    RETINAL    ARTERY.  487 

coat  of  the  vessels  is  also  thickened.  The  nerve  fibres,  both  in 
the  retina  and  on  the  disc,  freqnently  present  either  the  above- 
described  ganglion-lilvc  swellings  or  a  simple  hypertrophy.  Atro- 
phy of  the  ganglion  cells  and  nerve  fibres  appears  always  to  occur 
in  those  cases  which  go  on  to  blindness.  The  appearance  in  the 
nerve-fibre  layer  of  small,  round,  homogeneous  bodies,  having  an 
average  size  somewhat  greater  than  the  blood-corpuscles,  which  I 
observed  in  one  case,*  has  been  confirmed  by  Blessig.f 

We  have  also  a  description  of  the  anatomical  appearances  in 
one  of  those  rare  cases  in  which,  with  a  high  degree  of  intraocular 
swelling  of  the  nerve,  good  vision  was  retained.  IwanofF|  having 
had  an  opportunity  to  make  an  examination  in  such  a  case  of  so- 
called  "Stauungspapille,"  the  most  striking  microscopic  appear- 
ance was  a  great  hypersemia  of  all  the  vessels  and  a  dilatation  of 
the  capillaries,  so  that  the  great  mass  of  the  disc  was  composed 
of  vessels  resembling  a  telangiectasis.  The  connective  tissue  was 
slightly  hypertrophied  in  consequence  of  a  serous  saturation.  The 
nerve  fibres  had  not  suffered  any  change.  There  was  no  trace  of 
new  cellular  growths.  In  the  retina  were  no  changes  except  a 
hypersemia.  Mauthner's§  report,  which  evidently  refers  to  the 
same  case,  states  that  there  were  signs  of  an  interstitial  neuritis, 
consisting  in  a  proliferation  of  the  connective  tissue  in  a  portion 
of  the  optic-nerve  trunk,  which  remained  attached  to  the  eyeball. 

EMBOLISM    OF    THE    CENTRAL    RETINAL   ARTERY. 

Embolism  of  the  central  retinal  artery  as  a  cause  of  sudden 
blindness  was  first  observed  by  Von  Graefe.||  The  ophthalmo- 
scopic appearance  when  the  patient  first  presented  himself,  about 
a  week  after  the  blinding,  was  essentially  as  follows.  The  refract- 
ing media  were  clear,  the  optic  nerve  quite  white,  but  not  opaque, 
as  in  atrophy,  but  normally  translucent.  All  the  vascular  trunks 
upon  the  optic  disc  were  greatly  contracted.  The  principal  arteries 
upon  the  retina  appeared  like  delicate  lines,  and  their  branches 
were  correspondingly  small.     The  veins,  too,  were  in  all  places 

*  Arch.  f.  Ophth.,  B.  vii.  2,  pag.  63. 

t  Petersburger  med.  Zeitung,  1866,  pag.  76. 

X  Klin.  Monatsbl.  f.  Augenheilk.,  1868,  pag.  421. 

g  Lehrbuch  der  Ophthalmoscopie,  pag.  293. 

II  Arch.  f.  Ophth  ,  B.  v.  1,  pag.  136. 


488  EMBOLISM    OF   THE    CENTRAL    RETINAL    ARTERY. 

thinner  than  normal,  but  largest  near  the  equator.  After  a  few 
clays  a  very  peculiar  phenomenon  of  circulation  was  observed  in 
the  retinal  veins.  There  appeared  to  be  an  uneven  filling  of 
the  veins, — that  is,  a  portion  of  the  vein  would  be  well  filled 
and  an  adjoining  portion  comparatively  empty.  Upon  fixing 
the  attention  sharply  upon  one  particular  part  of  a  vessel,  it  could 
be  seen  that  the  blood  moved  by  arhythmic  impulses  toward  the 
optic  disc,  now  moving  forward,  and  again  standing  quite  still. 

Toward  the  end  of  the  second  week  the  retina  in  the  region  of 
the  macula  lutea  began  to  grow  opaque.  A  gray-white  infiltration 
appeared,  which  extended  to  the  temporal  margin  of  the  optic  disc, 
and  shaded  off  about  its  periphery  imperceptibly  into  healthy 
tissue. 

The  position  of  the  fovea  centralis  was  occupied  by  a  dark 
cherry-red  spot  about  one-quarter  the  size  of  the  optic  disc.  The 
color  of  this  spot  was  so  intense  as  to  suggest  at  once  the  suspicion 
of  a  hemorrhage.  Still,  it  appeared  more  proper  to  regard  the 
eflTect  as  due  to  a  contrast  in  color,  for  while  the  surrounding 
infiltrated  retina  by  its  opacity  hid  the  choroid,  that  portion  in 
the  immediate  neighborhood  of  the  fovea  centralis  remained  free 
from  infiltration  and  allowed  the  choroid  more  distinctly  to  shine 
through.  In  the  course  of  two  or  three  weeks  the  infiltration  dis- 
appeared, and  with  its  disappearance  the  intense  cherry-red  color 
of  the  macula  lutea  passed  imperceptibly  into  a  light-browiji 
color  not  differing  essentially  from  that  of  the  neighboring  parts. 
There  was  and  continued  to  be  only  the  slightest  percej)tion  of 
light.     Gradually  there  came  on  atrophy  of  the  optic  nerve. 

The  examination  of  the  heart  showed  with  certainty  a  stenosis 
of  the  aortic  valves,  probably  in  connection  with  a  still  active 
endocarditis. 

About  a  year  later  the  patient  succumbed  to  his  heart  disease, 
and  through  the  kindness  of  the  attending  physician  I  came  into 
possession  of  the  blinded  eye.  Anatomical  examination  fully  con- 
firmed the  diagnosis.  The  arteria  centralis  retinae,  at  the  lamina 
cribrosa,  was  completely  occluded  by  an  embolus  which  had  forced 
its  way  up  to  this  point,  but  here  in  the  lamina  cribrosa,  where  no 
more  room  was  to  be  gained,  it  remained  fast.  On  the  cardiac 
side  of  the  embolus  the  artery  was  filled  by  a  thrombus. 

Atrophy  of  the  retina  about  the  optic  disc  could  be  distinctly 


EMBOLISM    OF   THE    CENTRAL    RETINAL    ARTERY.  489 

recognized;  the  lamina  cribrosa  was  covered  only  with  atrophied 
tissue.* 

Since  this  first  publication  by  Von  Graefe  a  great  number  of 
cases  have  been  described  as  embolism  of  the  central  artery.  In- 
deed, for  a  long  time  it  appeared  to  be  fashionable  to  reckon  as 
such  all  cases  of  sudden  blindness  in  one  eye,  even  though  the 
blindness  may  have  existed  for  years  before  coming  under  ob- 
servation, or  even  cases  in  which  both  eyes  have  been  similarly 
affected,  the  one  after  the  other,  whether  the  source  of  the  embolus 
could  be  discovered  or  not.  In  this  connection  it  should  be  re- 
membered that  none  of  the  above  mentioned  symptoms  have  any 
pathognomonic  value. 

Sudden  blindness  with  notice^fble  contraction  of  the  arteries 
occurs  also  in  neuritis,  and  under  other  circumstances  which  do 
not  admit  the  idea  of  embolus  as  the  cause.  Thouo:h  we  cannot  in 
all  cases  account  for  these  sudden  obstructions  of  circulation  with 
simultaneous  loss  of  vision,  this  much  is  certain,  that  we  cannot 
diagnose  embolus  from  these  symptoms  alone. 

The  peculiarity  of  the  circulation  in  the  retinal  veins  was  first 
observed  by  E.  v.  Jaegerf  in  a  man  72  years  of  age,  who  had  be- 
come blind  during  the  previous  night.  Von  Graefe|  observed  it, 
too,  in  a  case  in  which  blindness  had  come  on  within  a  few  days, 
but  in  which  no  embolus  could  be  detected,  and  in  a  marked 
degree,  too,  in  the  asphyxiated  stage  of  cholera.  This  symptom 
depends  simply  upon  a  diminished  vis  a  fcrgo,  a  condition  which 
obtains  when  the  arteries  are  contracted  and  the  veins  conse- 
quently only  partially  filled.  But  even  when  an  embolus  has 
completely  closed  the  central  retinal  artery,  it  is  still  possible  for 
a  small  quantity  of  blood  to  reach  the  retina,  for,  as  Leber§  has 
shown,  a  communication  exists,  by  means  of  the  vascular  circle 
immediately  surrounding  the  optic  nerve,  between  the  vascular 
system  of  the  retina  and  the  ciliary  arteries.  Unfortunately,  how- 
ever, this  connection  is  only  of  a  capillary  nature,  and  not  suitable 

*  The  preparation  here  referred  to  is  still  in  my  possession,  and  has  been 
pronounced  fully  satisfactory  by  all  experts  who  have  seen  it.  Among  others, 
Profs.  Virchow  and  Cohnheim  were  kind  enough  to  examine  it. 

f  Ueber  Staar  und  Staaroperationen,  1853,  pag.  104  bis  109. 

X  Arch.  f.  Ophth.,  B.  ii.  2,  pag.  142  und  210. 

§  Ibid.,  B.  xi.  1,  und  B.  xviii.  pag.  31. 

32 


490  EMBOLISM    OF   THE    CENTRAL    RETINAL    ARTERY. 

for  the  establishment  of  a  compensating  collateral  circulation. 
Even  anastomoses  of  more  than  capillary  size,  if  they  existed, 
would  be  prevented  from  developing  by  the  unyielding  nature  of 
the  scleral  tissue  through  which  they  must  pass. 

The  peculiar  changes  about  the  macula  lutea  are  likewise  not 
specially  characteristic  of  embolus.  They  may  occur  without 
embolus,  and  in  many  cases  of  embolus  they  are  not  observed. 

The  interpretations  of  the  ophthalmoscopic  appearances,  more- 
over, are  at  variance,  some  authorities  regarding  them  as  hemor- 
rhages. 

At  all  events,  hemorrhages  have  been  stated  to  exist  in  a  large 
number  of  cases  which  have  been  described  as  embolisms.  They 
were  always  few  and  small,  and  occupied  the  surface  of  the  optic 
disc  or  its  immediate  neighborhood,  especially  on  the  side  toward 
the  macula  lutea.  These  considerations  bring  us  to  the  conclusion 
that  a  different  interpretation  must  be  put  on  at  least  a  part  of  the 
many  cases  which  have  been  described  as  embolism  of  the  central 
artery.  Thus,  for  instance,  sudden  blindness  in  one  eye  may 
be  caused  by  an  effusion  of  blood  in  the  orbital  portions  of  the 
optic  nerve,  and  present  a  condition  much  resembling  embolism.* 
There  occur,  moreover,  cases  of  sudden  blindness  in  both  eyes,  with 
ophthalmoscopic  appearances  very  like  embolism,  and  yet  no  one 
would  be  inclined  to  believe  in  a  simultaneous  occlusion  of  botli 
central  arteries  by  embolism.  If  this  be  so,  why  should  the  same 
symptoms  and  the  same  ophthalmoscopic  appearances,  when  they 
occur  in  only  one  eye,  be  assumed  in  all  cases  to  indicate  embolism  ? 

If  the  case  be  as  clear  as  that  first  published  by  Von  Graefe,  or 
that  confirmed  by  my  dissection,  if  a  period  be  observed  in  which 
there  is  no  infiltration,  and  the  only  symptoms  in  the  eye  are 
those  which  may  be  due  to  an  arrest  of  the  arterial  supply,  if  an 
arterial  or  cardiac  disease  furnish  the  source  for  an  embolus,  the 
diagnosis  need  not  be  doubtful.  If  the  last  named  symptom  be 
wanting,  it  would  awaken  the  suspicion  tliat  the  contraction  of  the 
arteries  might  be  a  consecutive  condition  caused,  for  instance,  by 
a  retrobulbar  neuritis.  The  occurrence  of  embolism  in  the  brain, 
with  a  perfectly  healthy  condition  of  the  circulatory  apparatus, 
has,  it  is  true,  been  observed,  and  the  breaking  down  of  clots  in 

*  Comp.  Magnus,  Die  Sehnervenblutungen,  Leipzig,  1874. 


ATROPHY    OF   THE    OPTIC   NERVE.  491 

the  heart  has  been  demonstrated  as  the  cause  of  such  an  occur- 
rence. Admitting  the  possibih'ty  of  an  analogous  process  for 
the  cases  under  consideration,  it  must  still  be  remembered  that 
processes  of  quite  a  different  nature  may  cause  an  apparently 
similar  effect  upon  the  retinal  arteries. 

Embolism  of  a  single  branch  of  the  central  retinal  artery  was 
first  demonstrated  by  Virchow,*  and  the  condition  has  been  recog- 
nized several  times  ophthalmoscopically. 

Aside  from  the  cases  above  referred  to,  there  have  been  but  two 
others  in  which  an  anatomical  examination  confirmed  the  diag- 
nosis of  embolism  of  the  central  artery  made  during  life.f 

ATROPHY  OF  THE  OPTIC  NERVE. 

The  symptoms  of  this  pathological  condition  consist  partly  in 
disturbances  of  vision  and  partly  in  changes  ophthalmoscopically 
visible  at  the  intraocular  extremity  of  the  optic  nerve.  The  dis- 
turbances of  vision  will  be  discussed  under  the  head  of  amblyopia 
and  amaurosis.  The  ophthalmoscopic  changes  may  be  compre- 
hended by  the  term  atrophic  degeneration  of  the  optic  nerve,  since 
they  are  the  consequences  of  some  one  of  the  various  diseases  which 
involve  a  partial  or  total  degeneration  of  the  optic-nerve  fibres. 

Tiie  principal  sign  of  an  atrophic  degeneration  is  a  change  in 
color,  by  which  the  optic  disc  grows  brighter. 

Simultaneously  the  lamina  cribrosa  may  be  hidden  by  an  opacity 
of  the  nerve  tissue,  or  it  may  remain  visible  and  indeed  be  more 
distinct  than  normal.  Frequently  the  optic  nerve  assumes  a 
peculiar  bluish  or  more  rarely  a  greenish-blue  color. 

The  ophthalmoscopic  examination  by  daylight,  as  described  on 
page  115,  may  be  employed  to  great  advantage  in  these  cases,  as 
indeed  it  may  for  all  diseases  of  the  optic  nerve  and  retina,  where 
it  is  desirable  to  recognize  slight  opacities  or  delicate  changes  of 
color. 

In  the  centre  of  the  disc,  or  over  that  portion  of  it  in  which  the 
lamina  cribrosa  is  visible,  its  white  net-work  of  connective  tissue 
will  be  seen  filled  with  bluish  dots  and  lines,  which  are  the  bun- 

*  Arch.  f.  path.  Anat.,  B.  x.  p.  181,  unci  Gesammelte  Abhand.,  pag.  719. 
fSichel,  Arch,  de  Physiologic,  t.   iv.,   1871-1872,  pag.  83;    H.  Schmidt, 
Arch.  f.  Ophtk,  B.  xx.  2,  pag.  286. 


492  ATROPHY    OF   THE    OPTIC   NERVE. 

dies  of  nerve  fibres  passing  through  it.  The  bhiish  color  must 
be  caused  by  a  change  in  the  fibres  themselves.  The  whitish 
discoloration  may  be  due  to  various  causes. 

In  the  first  place,  the  lamina  cribrosa  may  be  laid  bare  by  an 
atrophy  of  the  nerve  fibres  just  as  is  the  floor  of  a  physiological 
excavation ;  or  it  may  be  covered  by  a  proliferation  of  the  con- 
nective tissue,  accompanying  the  degeneration  of  the  nerve  fibres, 
thus  furnishing  a  surface  from  which  the  light  is  strongly  reflected. 

Finally,  as  Von  Graefe*  suggests,  it  may  safely  be  assumed 
that  an  obliteration  of  the  numerous  delicate  vessels  of  the  optic 
nerve  occurs  simultaneously  with  or  may  precede  the  atrophy  of 
the  nerve  fibres.  The  quantity  of  blood  in  the  optic  nerve  being 
diminished,  the  normal  rosy  tinge  of  its  disc  is  of  course  propor- 
tionately paler. 

The  discoloration  of  the  optic  disc,  and  the  more  distinct  ai>- 
pearance  of  the  lamina  cribrosa,  is  always  first  apparent  on  the 
temporal  half,  and  may  there  have  reached  a  development  to  be 
regarded  as  pathological,  while  the  median  half  still  retains  its 
normal  color.  This  is  as  might  be  expected,  for  both  the  bright 
spot  and  the  physiological  excavation  seen  in  the  normal  nerve 
always  occupy  the  lateral  half  of  the  disc,  while  tlie  great  mass 
of  the  nerve  fibres  passes  up  over  the  median  side.  A  beginning 
atrophy  of  the  nerves  Mould  therefore  first  manifest  itself  on  the 
temporal  side  of  the  disc  where  the  nerve  fibres  are  fewest. 

The  retinal  vessels  may  remain  unchanged  or  be  more  or  less 
contracted.  In  many  cases  this  may  be  due  to  the  fact  that  there 
is  simultaneous  disease  of  the  retina ;  or  the  central  artery  of  the 
retina  in  consequence  of  neurotic  changes  may  have  been  com- 
pressed in  the  ojitic  nerve  before  it  reaches  the  retina. 

H.  Miillerl  pointed'  out  still  another  consequence  of  the  atro- 
phy, and  described  it  as  atrophic  excavation. 

Normally,  the  nerve  fibres  at  their  place  of  entrance  form  a 
thick  layer,  which  at  the  margin  of  the  disc  exceeds  the  thickness 
of  all  the  other  layers  of  the  retina.  If  now  the  loss  of  substance 
caused  by  the  atrophy  of  the  nerve  fibres  be  not  replaced  by  a 
proliferation  of  the  connective  tissue,  the  place  of  entrance  of  the 

*  Klin.  MonatsbL,  1865,  pag.  131-  et  seq. 
f  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  92. 


ATROPHY    OF   THE    OPTIC   NERVE. 


493 


optic  disc  assumes  the  form  of  a  flat  depression,  -wliose  floor  is 
formed  by  the  lamina  cribrosa. 


Fig.  46. 


Fig.  46  represents  such  a  ease  in  longitudinal  section  of  the 
nerve.  The  preparation  is  from  a  case  of  a  high  degree  of  atro- 
phy of  the  optic  nerve,  and  presents  the  appearance  of  an  excava- 
tion. The  atrophied  nerve  fibres,  forming  a  thin,  striated  mem- 
brane, cover  the  lamina  cribrosa.  The  central  vessels  Vr,  at  the 
point  where  they  bend  over  upon  the  retina,  form  a  prominence 
above  its  surface,  for  in  the  retina,  too,  the  nerve-fibre  layer  is 
atrophied.  Remembering  that  in  such  cases  the  retina  generally 
remains  perfectly -transparent,  and  that  in  the  case  here  repre- 
sented the  lamina  cribrosa  and  the  tissue  covering  it  lie  exactly 
in  the  plane  of  the  choroid,  it  seems  probable  that  upon  ophthal- 
moscopic examination  this  case  would  not  have  presented  the 
appearance  of  an  excavation.  Perhaps  it  could  have  been  seen 
in  the  upright  image  that  the  retinal  vessels  upon  the  surface  of 
the  disc  were  at  a  deeper  level  than  those  on  the  adjoining  retina. 

Of  course  the  relations  would  be  different  in  case  of  atrophy  of 
the  optic  nerve  ensuing  where  there  was  previous  physiological 
excavation.  Under  such  circumstances  the  excavation  may  reach 
a  great  size  and  depth,  so  that  extreme  cases  can  no  longer  be 
distinguished  from  pressure  excavation  by  the  ophthalmoscopic 
examination  alone,  a  consideration  of  all  the  clinical  symptoms 
being  necessary  in  making  the  diagnosis. 

In  some  few  cases  of  atrophy  of  the  optic  nerve  more  or  less 
dark  pigment  has  been  seen  upon  the  surface  of  the  disc* 

*  E.  V.  Jaeger,  TJeber  Staar  und  Staaroperationen,  pag.  103,  Fig.  31  ;  Lieb- 
reich,  Klin.  Monatsbl.,  18G4,  pag.  229;  Knapp,  Arch,  f.  Ophth.,  B.  xiv.  1, 
pag.  252. 


494  GLIOMA   OF   THE   RETINA. 

It  is  to  be  remembered  that  even  under  physiological  relations, 
and  with  normal  vision,  pigment  is  found  in  the  optic  nerve.* 

The  anatomical  changes  which  occur  in  atrophic  degeneration 
of  the  optic  nerve  have  been  partially  described  under. the  head 
of  neuritis.  Both  anatomically  and  clinically  it  is  impossible  to 
separate  by  a  sharply  defined  line  a  retrobulbar  neuritis  from  an 
atrophic  process.  At  this  place,  therefore,  are  described  only  those 
changes  Avhich  both  from  a  clinical  and  an  anatomical  stand-point 
must  be  considered  as  belonging  to  the  atrophic  degeneration. 

According  to  Virchow,t  the  process  consists  in  atrophy  of  the 
nerve  fibres  and  changes  in  the  interfibrous  substance,  which 
either  becomes  oedematous,  or  corpora  amylacea  or  nucleated  cells 
develop  in  it.  The  disappearance  of  the  nerve  fibres  causes  a 
gray  transparent  appearance.  The  atrophy  may  not  essentially 
affect  the  retina,  and  may  be  limited  to  only  a  small  portion  of 
the  nerve. 

Virchow  distinguishes  two  kinds  of  gray  atrophy,  or  degenera- 
tion of  the  optic  nerve, — a  total  and  a  partial  or  mottled, — and 
he  commends  the  latter  specially  to  the  attention  of  ophthalmolo- 
gfsts,  as  it  frequently  occurs  in  connection  with  affections  of  the 
brain  or  spinal  cord.  "The  mottled  gray  atrophy  of  the  opticus 
ajipears  to  be  connected  especially  with  the  mottled  atrophy  of 
the  spinal  cord,  and  under  these  circumstances  amaurosis  is 
associated  Avith  paralysis  and  anaesthesia  of  the  extremities." 

Leberj;  calls  attention  to  the  advantages  of  the  chloride  of 
gold  reaction  as  a  method  by  w'hich  to  detect  optic-nerve  atrophy 
when  making:  an  anatomical  examination.  The  failure  of  this  re- 
action  at  certain  parts  of  the  nerve  shows  the  existence  of  atrophy. 

The  atrophy  of  the  optic  nerve  may  end  at  the  chiasm,  or  may 
exist  behind  it,  and  may  correspond  with  similar  changes  in  the 
thalami  optici  and  corpora  quadrigemina. 

GLIOMA   OF   THE   RETINA. 

The  tumors  which  Virchow§  designates  as  glioma  of  the  retina 

*  Liebreich,  Atlas  der  Ophthalmoscopic,  Taf.  xii.  Fig.  3  ;  E.  v.  Jaeger, 
•  Ophthalmoscopischcr  Handatlas,  Taf.  xvi.  Fig.  76. 
f  Arch.  f.  path.  Anat.,  B.  x.  pag.  192. 
+  Arch.  f.  Ophth.,  B.  xiv.  1,  pag.  164. 
2  Geschwiilste,  ii.  pag.  151  bis  167. 


GLIOMA    OF   THE   RETINA.  495 

resemble  macroscopically  the  white  substance  of  the  brain,  and 
are  in  fact  identical  with  that  form  of  tumor  formerly  described 
as  encephaloid,  or  medullary  sarcoma  of  the  retina.  • 

The  principal  mass  of  the  tumor,  according  to  Virchow,  con- 
sists of  countless  nuclei  and  cells.  The  first  correspond  often 
with  the  small,  round,  glistening  nuclei  of  the  granular  layer ;  at 
other  times  they  are  larger  and  more  granulated.  The  cells  are 
likewise  small,  and  are  generally  round,  though  sometimes  of 
irregular  shape,  and  provided  with  delicate  processes.  Here  and 
there  can  be  seen  fibre  cells  with  very  long  processes,  and  very 
short,  thin  cell  bodies.  They  are  sometimes  isolated,  and  some- 
times several  are  connected  together. 

The  development  of  these  cellular  elements  takes  place  mostly 
in  the  external  granular  layer,  as  appeared  from  a  case  which  I  ex- 
amined,* and  as  was  confirmed  later  by  Hirschberg.f  IwanoifJ 
has  further  shown  that  glioma  may  be  developed  from  the  con- 
nective-tissue cells  in  the  nerve-fibre  layer,  and,  moreover,  that 
the  cells  of  the  adventitial  coat  of  the  vessels  may  participate  in 
the  process.  But  little  intercellular  substance  can  be  seen.  The 
tumor,  when  fresh,  appears  as  an  amorphous,  finely  granulated 
mass,  and  when  hardened  shows  a  fine  reticulated  character.  The 
tissue  is  traversed  in  all  directions  by  vessels,  some  of  which  are 
widely  dilated.  When  the  tumor,  at  last,  breaks  through  the  eye 
and  assumes  an  external  growth,  the  vessels  multiply  greatly, 
and  from  this  circumstance  comes  the  name  "  fungus  haematodes" 
formerly  applied  to  such  growths. 

In  glioma  of  long  standing  are  found  many  signs  of  degenera- 
tion, particularly  fatty  and  calcareous  masses.  In  rare  instances 
tumors  occur  of  a  form  intermediate  between  glioma  and  sarcoma. 
Virchow  has  designated  them  as  "gliosarcoma." 

Von  Graefe§  has  described  the  clinical  course  of  glioma  in  his 
usual  masterly  style. 

The  first  stages  of  its  development  seldom  come  under  observa- 
tion, for  the  patients  are  generally  small  children,  who  do  not 
complain  of  any  disturbances  of  vision,  and  the  attention  of  the 


*  Arch.  f.  Ophth.,  B.  vi.  2,  pag.  324. 
f  Ibid.,  B.  xiv.  2,  pag.  30. 
X  Ibid.,  B.  XV.  2,  pag.  69. 
^  Ibid.,  B.  xiv.  2,  pag.  103. 


496  GLIOMA    OF    THE    RETINA. 

parents  is  first  called  to  the  condition  by  the  peculiar  reflex  from 
the  fundus  of  the  eye,  which  is  seen  by  feeble  illumination  when 
the  pupil  is  dilated. 

It  is  easier  to  observe  the  first  stage  when  the  disease  affects 
somewhat  older  children  or  adults.  Ophthalmoscopic  examina- 
tion reveals  peculiar  and  generally  very  numerous  white  spots  of 
various  sizes  upon  the  retina,  differing  essentially  in  their  opacity, 
form,  and  grouping  from  other  retinal  infiltrations.  These  spots 
at  places  lie  immediately  behind  the  vessels  of  the  retina,  while 
at  other  places  they  extend  through  its  whole  thickness,  hiding 
portions  of  the  vessels,  and  very  early  becoming  elevated  above 
the  general  surface. 

These  changes  are  always  soon  followed  by  detachment  of  the 
retina.  The  retina  and  the  tumor  growing  from  it  are  gradually 
pressed  forward,  causing  the  peculiar  reflex  from  the  tumor  and 
the  details  of  the  anomalous  surface  to  become  still  more  ap- 
parent. By  ophthalmoscopic  or,  still  better,  by  focal  illumination 
the  tumor  can  now  be  seen  as  a  brilliant  white  prominence,  or  at 
certain  points  it  may  be  covered  with  newly  developed  vessels, 
essentially  different  in  appearance  and  arrangement  from  those 
of  the  retinal  system.  Tiie  reflex  will  accordingly  be  either  a 
chalky  white  or  a  yellowish  red,  with  an  interplay  of  colors  if 
the  anterior  surface  be  smooth.  This  peculiar  reflex  from  the 
fundus  of  a  blind  eye  was  first  described  by  Beer  under  the  name 
of  "  amaurotic  cat's  eye." 

The  optical  conditions  for  such  a  reflex  exist  when  a  bright- 
colored  body  lies  immediately  behind  a  transparent  lens.  Such 
a  pupillary  reflex  may  therefore  be  caused  by  pus  or  new-formed 
layers  of  tissue  in  the  vitreous  or  by  secondary  metamorphoses  in 
a  detached  retina.  But  the  best  example  of  this  reflex  is  fur- 
nished by  a  glioma  of  the  retina.  A  very  bright  white  reflex 
from  the  fundus  can  be  caused  by  scarcely  anything  else. 

There  may  be  pigment  in  the  tumor  as  the  result  of  hemor- 
rhage, but  except  as  caused  in  this  way  it  is  absent.  This  and 
the  absolute  transparency  of  the  vitreous  in  front  of  the  tumor 
furnish  the  conditions  which  make  possible  such  a  striking  illu- 
mination of  the  pupil  as  is  not  seen  in  any  other  affection. 

The  steady  growth  of  the  tumor  is  generally  accompanied  by 
an  increase  of  intraocular  pressure.     There  ensues  a  glaucomatous 


GLIOMA    OF   THE    EETINA.  497 

condition,  characterized  by  diffuse  clouding  of  the  cornea,  dilata- 
tion of  the  pupil,  hypertemia  of  the  large  veins,  running  in  and 
beneath  the  conjunctiva,  often,  too,  by  cataract.  The  diagnosis 
is  based  upon  the  facts  that  even  where  cataract  exists  the  reflex 
can  be  recognized  as  coming  from  the  depth  of  the  eye,  and 
further,  that  in  children  glaucoma  is  almost  never  a  primary  dis- 
ease, but  generally  a  secondary  one. 

Frequently  in  the  course  of  glioma  there  occurs  an  intraocular 
inflammation  of  a  decidedly  purulent  character,  which  ends  in 
atrophy  of  the  eyeball.  Von  Graefe  thought  the  cause  of  this 
purulent  choroiditis  to  be  the  above  mentioned  peculiar  degenera- 
tion of  the  glioma,  by  which  the  tumor  becomes  filled  with  fatty 
and  calcareous  masses,  and  thus  breaks  down  into  a  granular, 
flocculent  pap.  Suppuration  of  the  cornea  is  a  rarer  cause  of 
choroiditis. 

The  course  of  the  disease  is  generally  not  checked  by  this 
intercurrent  shrinking. 

The  extraocular  growth  of  the  tumor  is  always  along  the  course 
of  the  optic  nerve,  and  this  process  may  begin  at  a  time  when  the 
intraocular  tumor  has  attained  but  a  moderate  size. 

The  beginnings  of  the  degenerative  process  in  the  opticus  can 
be  demonstrated  only  microscopically.  Later,  there  occurs  a 
swelling  of  the  nerve  substance  proper,  while  the  sheath  becomes 
thickened  by  an  indifferent  hyperplasia.  At  last  the  condition 
becomes  such  that  the  swollen  or  degenerated  optic  nerve  cannot 
be  recognized  in  the  morbid  growth  which  fills  the  orbit. 

The  development  of  the  tumor  in  the  eye  is  generally  continu- 
ous, but  it  may  be  characterized  by  the  appearance  of  new  centres 
of  development.  Thus,  in  a  case  described  by  Rindfleisch*  there 
was  besides  the  retinal  glioma  filling;  all  the  interior  of  the  eve  a 
circumscribed  gliomatous  growth  separated  from  it,  between  the 
choroid  and  the  sclera. 

If  the  entire  interior  of  the  eye  be  filled,  there  ensues  at  last  a 
rupture  forward,  generally  at  the  margin  of  the  cornea,  or  through 
it,  or,  more  rarely,  through  the  sclera.  When  thus  exposed  to  the 
air,  the  tumor  assumes  a  dark-red  appearance,  bleeds  copiously  on 
slight  provocation,  and  grows  with  great  rapidity. 

*  Klin.  Monatsbl.  f.  Augenheilk.,  1863,  pag.  347. 


498  GLIOMA    OF   THE   RETINA. 

It  is  exceedingly  difficult  to  determine  from  the  symptoms,  the 
time  when  the  optic  nerve  becomes  involved.  As  the  nerve  in- 
creases more  in  a  transverse  than  in  a  longitudinal  direction,  the  eye 
is  not  perceptibly  crowded  forward,  as  happens  when  large  tumors 
develop  in  the  orbital  tissues.  According  to  Von  Graefe,  the 
signs  by  which  to  recognize  a  degeneration,  swelling,  and  rigidity 
of  the  optic  nerve  are  that  the  eye  is  driven  from  1  to  2  ram. 
forward,  and  at  the  same  time  tliere  is  a  slight  stiffiiess  of  move- 
ment, so  that  the  eye  affected  falls  slightly  behind  the  other  in 
concomitant  movements. 

Moreover,  upon  pressure  made  on  the  eye  in  a  direction  toward 
the  bottom  of  the  orbit  the  resistance  is  greater  than  normal,  and 
the  natural  depression  between  the  eye  and  the  orbital  wall  is 
obliterated. 

Of  course  these  symptoms  can  be  expected  only  when  the  disease 
of  the  nerve  is  somewhat  advanced.  Its  beo-inninoj  cannot  be 
recognized,  but  there  is  always  reason  to  fear  it  when  the  tumor 
within  tiie  eye  has  attained  a  considerable  size  and  has  existed  a 
long  time.  If  rupture  occur  at  the  anterior  part  of  the  eye,  or  if 
the  eye  be  forced  forward  by  growths  in  the  orbit,  it  is  certain 
that  disease  of  the  nerve  has  long;  existed. 

After  the  fatty  tissue  of  the  orbit  is  once  affected,  the  growth 
increases  very  rapidly.  The  same  is  the  case  when  the  tumor 
breaks  through  the  anterior  part  of  the  eye,  and,  aside  from  the 
mere  growth,  inflammatory  and  hemorrhagic  processes  are  set  up. 

The  bony  walls  of  the  orbit  remain  long  unaffected,  but  the  path- 
ological process  reaches  the  cranial  cavity  along  the  optic  nerve, 
generally  by  a  steady  progression,  but  sometimes,  particularly  at 
a  late  stage,  as  if  by  sudden  leaps.  ^letastases  have  been  observed 
in  distant  organs,  for  instance,  in  the  diploe  of  the  skull,  the  liver, 
the  ovaries,  and  the  retro-peritoneal  tissue.* 

Retinal  glioma  is  almost  exclusively  a  disease  of  childhood,  and 
probably  also  occurs  congenitally.  Only  very  exceptionally  does 
it  develop  in  adults. 

That  hereditary  causes  have  something  to  do  with  it,  is  shown 
by  the  fact  that  it  has  been  observed  in  several  cases  to  occur  in 

*  Knapp,  Die  intraocularen  Geschwiilste,  1868,  pag.  5  ;  Schiess-Gemuseus, 
Virchow's  Arch.,  B.  xlvi.  Heft  3;  Heyinann  und  Fiedler,  Arch.  f.  Ophth., 
B.  XV.  2,  pag.  173. 


GLIOMA   OF   THE   RETINA.  499 

different  members  of  the  same  family.  Von  Graefe  reports  two 
such  cases.  In  one  family,  among  six  or  seven  brothers  and  sisters, 
two  were  affected  in  childhood  with  glioma.  In  the  other,  the 
mother  of  a  child  affected  with  glioma  had  lost  several  brothers 
and  sisters  during  infancy  by  "  cancer  of  the  eye." 

The  assertion  made  by  some  authors  that  glioma  of  the  retina 
must  have  an  inflammatory  origin,  Von  Graefe  regards  as  un- 
doubtedly erroneous.  Inflammatory  processes  occur  in  the  course 
of  glioma  after  the  tumor  has  attained  a  considerable  development, 
but  they  are  not  the  occasion  for  its  beginning. 

According  to  Von  Graefe,  the  course  of  the  disease  is  uninter- 
ruptedly progressive.  He  does  not  admit  the  occurrence  of  pauses, 
as  described  by  Mackenzie  and  othei's.  Between  the  time  of  the 
first  observation  of  the  disease — that  is,  from  that  stage  when  only 
a  small  portion  of  the  interior  of  the  eye  is  filled  with  the  tumor 
until  it  attains  a  perceptible  extraocular  development — there  inter- 
venes a  period  of  from  one  to  three  years. 

The  absorption  of  a  retinal  glioma  is,  according  to  Von  Graefe, 
not  conceivable.  The  observations  which  have  been  thought  to 
show  the  possibility  of  such  a  thing  must  be  interpreted  as  mere 
shrinkages  of  the  eye,  and  of  a  transitory  character. 

It  is  finally  to  be  mentioned  that  glioma  not  infrequently  occurs 
in  both  eyes.  Generally  the  second  eye  is  attacked  after  the  dis- 
ease is  already  far  advanced  in  the  first.  Anatomical  examination 
has  shown  that  this  does  not  occur  by  simple  extension  through 
the  chiasm.  This  bilateral  disease  may  perhaps  be  regarded  as  a 
metastasis,  if  it  be  not  sufficient  to  regard  this  as  parallel  with 
those  frequent  cases  in  which  diseases  occur  simultaneously  in 
both  eyes  without  any  known  causes. 

Treatment  furnishes  no  very  satisfactory  results.  The  indica- 
tion surely  exists  for  as  early  an  extirpation  as  possible,  and  offers 
at  least  the  hope  of  saving  the  life,  when  the  intraocular  tumor 
is  small  and  the  optic  nerve  is  not  yet  affected.  If,  however,  the 
intraocular  tumor  be  already  far  developed,  and  the  disease  have 
extended  to  the  nerve,  extirpation  seems  only  to  hasten  the  fatal 
result. 

It  has  already  been  remarked  that  the  beginning  of  degenera- 
tion in  the  optic  nerve  cannot  be  diagnosed  ;  but  its  existence  is 
always  to  be  assumed  when  the  disease  has  lasted  a  long  time,  and 


500  GLIOMA    OF   THE    RETINA. 

wlien  the  interior  of  the  eye  is  entirely  filled  with  the  tumor. 
Von  Graefe,  therefore,  advises  in  these  cases,  in  making  the  extir- 
pation, to  divide  the  optic  nerve,  not  as  usual  with  the  scissors, 
but  with  a  neurotome,  and  as  far  back  in  the  orbit  as  possible. 

After  decided  degeneration  of  the  optic  nerve  is  once  estab- 
lished, tlie  local  reappearance  of  the  disease  in  the  orbit  generally 
occurs  within  a  few  months  after  the  extirpation.  Even  in  cases 
where  the  cross-section  of  the  optic  nerve  made  during  the  opera- 
tion appeared,  both  macroscopically  and  microscopically,  to  be 
perfectly  normal,  reappearance  of  the  disease  in  the  orbit  has  been 
observed  within  a  year. 

Further  experience  must  decide  the  question  whether  better 
results  are  to  be  obtained  by  a  periosteal  extirpation  of  the  entire 
contents  of  the  orbit  (see  page  200). 


GLAUCOMA. 


The  real  nature  of  glaucoma  was  first  understood  when  an  ab- 
normal increase  in  the  intraocular  pressure  came  to  be  regarded  as 
the  essential  element  in  the  disease.  It  was  known  to  the  older 
ophthalmologists  that  in  glaucoma  the  eye  becomes  abnormally 
hard,  but  tlie  fundamental  importance  of  this  increase  in  intra- 
ocular pressure  was  first  appreciated  and  pointed  out  by  Yon 
Graefe. 

Von  Graefe  regarded  glaucoma  as  essentially  an  inflammatory 
disease  which  might  be  called  a  secreting  choroiditis,  but  Donders 
showed  that  an  intraocular  pressure  might  exercise  its  deleterious 
influence  upon  vision,  entirely  independent  of  inflammation. 

Donders,  therefore,  regarded  the  increased  pressure  as  in  itself 
the  essential  cause  of  glaucoma,  and  the  occurrence  of  the  inflam- 
mation as  an  exceedingly  frequent  complication. 

Since  the  increase  of  intraocular  pressure  may  reach  a  very  high 
degree  without  the  occurrence  of  any  inflammatory  symptoms,  an 
inflammation  cannot,  at  least  for  these  cases,  be  regarded  as  the  cause 
of  the  increased  pressure.  It  in  no  way  relieves  the  difficulty  to  re- 
gard the  increased  pressure  as  the  consequence  of  an  inflammatory 
process.  No  inflammation  of  the  eye,  not  even  acute  choroiditis, 
causes  by  itself  an  actual  and  permanent  increase  of  the  intraocular 
pressure.  Even  copious  inflammatory  exudations,  for  instance, 
in  detachment  of  the  retina,  generally  do  not  cause  an  increase 
of  pressure,  but  rather  a  compensating  resorption  of  the  vitreous 
body.  The  question  then  always  recurs,  why  it  is  that  in  secreting 
choroiditis  there  is  an  increase  of  pressure,  and  we  are  driven 
to  the  conclusion  that,  in  the  inflammatory  as  well  as  in  the 
non-inflammatory  cases,  there  must  be  some  modification  of  the 
physiological  laws  which  govern  the  secretion  of  the  ocular  fluids. 

Ludwig  showed  that  the  secretion  of  the  submaxillary  gland 
was  regulated  by  the  nerves.  Donders  assumed  a  similar  relation 
as  regulating  the  secretion  of  the  ocular  fluids,  and  regarded  the 

501 


502  GLAUCOMA   SIMPLEX. 

fifth  nerve  as  the  one  which  controlled  these  secretions,  since 
after  its  division  and  in  certain  cases  of  its  paralysis,  an  evident 
decrease  in  tension  was  observed.* 

Griinhagen  and  Hippelf  found,  also,  that  by  electric  irritation 
of  the  root  of  the  fifth  nerve  an  immediate  and  very  remarkable 
increased  intraocular  pressure  was  caused. 

According  to  Donders,  the  primitive  form  of  glaucoma  (glau- 
coma simplex)  is  represented  by  those  cases  in  which  there  is 
simply  increased  pressure,  but  no  apparent  inflammation,  while 
those  cases  which  are  complicated  by  inflammation  are  classified  as 
glaucoma  cum  ophthalmia,  or  as  inflammatory  glaucoma. 

In  defining  the  two  forms,  it  is  to  be  noticed  that  cases  of  in- 
flammatory glaucoma  may  gradually  pass  over  into  a  non-inflam- 
matory condition.  Still,  my  experience  satisfies  me  that  all  cases 
in  which,  during  the  course  of  the  disease,  there  has  been  glauco- 
matous inflammation,  even  thougJi  transitory,  must  be  regarded 
as  inflammatory  glaucoma. 

GLAUCOMA  SIMPLEX. 

All  the  symptoms  of  glaucoma  simplex  may  be  traced  back  to 
a  very  gradual  increase  in  the  intraocular  pressure.  At  first  this 
increase  in  pressure  is  often  very  slight  and  difficult  to  recognize 
by  the  sense  of  touch,  even  though  excavation  of  the  optic  disc 
due  to  pressure  be  already  taking  place.  In  the  later  stages  the  eye 
offers  greater  resistance  to  touch,  and  often  becomes  stone  hard. 

The  consequences  of  this  gradual  increase  of  pressure  appear 
first  in  a  change  of  form  of  the  optic  disc.  According  to  hydro- 
static laws,  the  intraocular  pressure  acts  uniformly  upon  every  part 
of  the  membranous  envelope  of  the  vitreous  body.  The  place  of 
entrance  of  the  optic  nerve  is,  however,  a  weak  point,  because  just 
here  the  sclera  is  penetrated  by  the  nervous  fascicles,  and  it  is 
therefore  plain  that  just  at  this  place  it  will  first  yield  to  the 
increased  pressure. 

The  essential  anatomical  character  of  this  excavation  consists 
in  this,  that  the  lamina  cribrosa  is  compressed  and  forced  back- 

*  Arch.  f.  Ophth.,  B.  ix.  2,  pag.  21G;  Klin.  Monatsblatt  fur  Augenheil- 
kunde,  1864,   pug.  434. 

t  Arch.  f.  Ophtli.,  B.  xiv.  3,  pag.  219,  und  B.  xv.  1,  pag.  265. 


PEESSUEE   EXCAVATION. 


503 


ward  behind  the  general  inner  surface  of  the  sclera,  often  so  far 
that  the  floor  of  the  excavation  lies  posterior  to  the  outer  surface 
of  the  sclera.  The  place  of  entrance  of  the  optic  nerve  is  now 
occupied  by  a  hollow,  its  lioor  formed  by  the  lamina  cribrosa 
and-  its  walls  by  the  sclera.  It  is  filled  partly  by  the  vitreous 
body,  and  partly  by  the  degenerated  tissue  of  the  optic  nerve, 
lying  above  the  lamina  cribrosa. 

Fig.  47. 


2?,  retina;  C7(,  choroid  ;  T'c,  central  vessel*.  The  walls  of  the  excavation  ai-e  covered  with  an 
ill-defined  tissue,  consisting  of  the  remains  of  the  terminal  fibres  of  the  optic  nerve  and  of  the 
vitreous  body.    Its  floor  is  funnel-shaped,  due  to  the  dilatation  of  the  central  canal  of  the  retinal 

vessels. 

The  excavation  is  often  kettle-shaped,  which  may  be  explained 
partly  by  the  anatomical  structure  of  the  lamina  cribrosa.  That 
part  of  the  optic  nerve  which  penetrates  the  sclera  is  often  not  a 
simple  cylinder,  but  is  enlarged  at  certain  places  in  such  a  way 
that  the  greatest  diameter  of  the  lamina  cribrosa  is  greater  than 
the  foramen  choroidere,  and  lies  posterior  to  it.  When  an  optic 
nerve  so  formed  becomes  excavated,  a  kettle-shaped  depression 
must  necessarily  result.  Moreover,  the  same  pressure  which  forced 
the  lamina  cribrosa  backward  acts  upon  the  lateral  walls  of  the 
excavation  itself,  tending  thus  to  bulge  them  outward. 

The  retinal  vessels,  together  with  the  remnants  of  the  nervous 
elements,  lying  upon  the  lamina  cribrosa,  are  naturally  at  the 
same  time  forced  against  the  walls  of  the  excavation,  and  since 
the  greater  part  of  them  pass  over  to  the  median  side  of  the 
optic  nerve,  they  mount  also  up  the  median  lateral  wall  of  the 


504  PRESSURE   EXCAVATION. 

excavation.  When^  after  a  protracted  glaucomatous  process,  the 
excavation  has  become  very  deep,  it  may  happen  that  the  vas- 
cular canal  in  the  centre  of  the  optic  nerve  becomes  distended. 
The  vessels  are  thereby  forced  against. the  median  lateral  wall 
of  the  excavation,  and  it  may  happen  that  upon  ophthalmo- 
scopic examination  the  floor  of  the  excavation  appears  destitute 
of  vessels. 

In  the  ophthalmoscopic  view  of  the  pressure  excavation  special 
notice  is  to  be  taken  of  the  sharp  border  lying  in  the  plane  of 
the  choroid,  and  also  of  the  floor  of  the  excavation.  The  latter 
presents  generally  the  characteristic  appearance  of  the  lamina 
cribrosa, — that  is,  a  net-work  of  connective  tissue,  having  rounded 
or  oval  meshes,  penetrated  and  filled  by  the  fascicles  of  nerve 
fibres,  which  are  of  a  bright-gray  color. 

At  the  point  where  the  retinal  vessels  pass  over  the  sharp  edge 
of  the  excavation  they  experience  a  compression,  which,  when 
the  increased  pressure  is  very  great,  and  especially  when  it  has 
developed  very  rapidly,  causes  a  stasis  of  blood  in  the  veins. 
Oftener,  and  generally  most  striking  in  the  case  of  the  veins, 
there  is  another  change  in  the  ophthalmoscopic  appearance  of  the 
retinal  vessels.  They  appear  to  end  in  hook-shaped  extremities 
at  the  point  where  they  bend  over  the  edge  of  the  excavation 
to  descend  upon  its  lateral  wall,  while  the  portions  of  vessels 
visible  upon  the  floor  of  the  excavation  appear  to  be  sharply  cut 
off"  at  the  point  where  they  are  hidden  by  the  overhanging  edge. 

These  vessels  also,  although  actually  continuous  by  a  portion  of 
their  trunks  not  visible,  appear  as  if  displaced  from  one  another 
laterally.  This  may  be  understood  by  remembering  that  during 
the  ophthalmoscopic  examination  we  cannot  see  the  excavation 
from  various  points  of  view,  but  only  through  the  pupil  of  the 
eye  under  examination. 

Generally  the  entire  median  wall  of  the  excavation  is  invisible, 
which  explains  fully  the  above  described  appearance  of  the  vessels. 

More  frequently  it  is  possible  to  see  tiie  wall  on  the  temporal 
side  of  the  excavation  in  its  whole  extent  from  the  choroidal 
margin  to  the  lamina  cribrosa,  and  to  appreciate  the  angle  which 
it  forms  with  the  latter.  One  can  follow  the  curves  of  the  fine 
retinal  vessels  as  they  pass  from  the  floor  to  the  wall  of  the  ex- 
cavation, and  again  when  they  leave  the  wall  to  spread-  out  upon 


PRESSURE    EXCAVATION.  505 

the  plane  of  the  retina.  In  such  cases  the  lateral  wall  often 
appears  of  a  light-brown  color,  on  account  of  the  pigment  con- 
tained in  this  part  of  the  sclera. 

The  depth  of  the  excavation  may  be  calculated  from  the  optical 
difference  of  the  correcting  lenses  needed  to  see  distinctly.in  the 
upright  image,  first  the  plane  of  the  retina,  and  then  tiie  floor  of 
the  excavation.  In  the  inverted  image  the  difference  in  parallax, 
produced  by  moving  the  convex  lens,  is  directly  dependent  upon 
the  difference  of  level.  One  must  notice  also  that  in  slight  move- 
ments of  the  convex  lens  the  entire  margin  of  the  excavation 
moves  over  the  floor.  If  the  movements  of  the  convex  lens  be 
made  at  right  angles  to  the  course  of  some  particular  retinal  ves- 
sel, one  can  see  distinctly  that  the  portion  of  the  vessel  lying  in 
the  plane  of  the  retina  appears  to  move  farther  than  that  portion 
upon  the  floor  of  the  excavation.  The  greater  the  parallax  the 
deeper  the  excavation. 

The  margin  of  the  excavation  is  often  surrounded  by  a  narrow 
bright  ring.  I  have  satisfied  myself  from  anatomical  examina- 
tion that  this  is  due  to  an  atrophy  of  the  choroid  surrounding 
the  optic  disc.  I  found  the  choroid  to  be  changed  in  this  place  to 
a  very  thin,  absolutely  transparent  membrane,  just  as  in  a  high 
degree  of  atrophy  caused  by  elongation  of  the  axis  of  the  eye, 
except  with  this  difference,  that  in  myopia  the  absolutely  atrophied 
portion  merges  gradually  into  the  normal  choroid,  while  the 
atrophied  part  of  the  choroid  surrounding  an  excavation  is  sharply 
bounded  by  the  normal  choroidal  tissue.  The  cause  of  the  atrophy 
is  probably  this,  that  often  very  considerable  bundles  of  fibres 
run  from  the  choroidal  ring  into  the  lamina  cribrosa,  and  when 
this  last  is  forced  backward  the  tension  is  extended  to  the  choroidal 
ring,  causing  its  atrophy.  It  is  only  seldom  that  the  form  of  the 
atrophied  portion  is  serrated  instead  of  annular. 

It  often  happens  also  that  the  atrophied  choroidal  ring  is 
staphylomatous.  In  these  cases  the  excavated  optic  disc  is 
surrounded  by  a  small  annular  scleral  ectasia,  which  of  course 
supports  a  part  of  the  pressure,  which  otherwise  would  have 
caused  more  rapid  destruction  of  vision. 

With  slight  practice  in  ophthalmoscopic  examination  a  fidly 
developed  pressure  excavation  can  scarcely  be  overlooked,  and 
still  under  certain  circumstances  there  may  be  considerable  diffi- 

33 


506  '  PRESSURE   EXCAVATION. 

culty  in  diagnosis,  since  physiological  excavations  due  to  senile 
changes,  or  still  more  to  atrophy  of  the  optic  nerve,  may  assume 
forms  scarcely  to  be  distinguished  from  pressure  excavations. 

The  physiological  excavation  is  in  its  typical  form  not  less 
characteristic  than  the  glaucomatous.  Nevertheless  it  is  probable 
that  in  advanced  age,  perhaps  from  senile  atrophy  of  the  connect- 
ive tissue,  a  physiological  excavation  may  become  unusually  deep 
and  broad,  so  that  it  approaches  upon  all  sides  the  border  of  the 
optic  disc.  Moreover,  the  sharpness  of  the  margin  and  the  steep 
walls  of  the  excavation  furnish  no  certain  diagnostic  criteria,  since 
the  margin  of  the  physiological  excavation  may  also  be  very  sharp 
and  its  walls  very  steep. 

One  must  pronounce  for  the  existence  of  a  pressure  excavation 
when  a  sharp  margin  and  steep  wall  coincide  with  the  margin  of 
the  optic  disc, — that  is,  with  the  inner  nerve  sheath, — and  so,  too, 
in  cases  where  the  excavation  is  only  partial,  so  that  a  part  of  the 
optic  disc  lies  in  its  normal  plane. 

The  greatest  diagnostic  difficulty  is  when  atrophy  of  the  optic 
nerve  develops  where  there  was  previously  a  deep  physiological 
excavation. 

The  excavation  becomes  by  the  degeneration  pf  the  nervous 
elements  deeper  and  broader,  its  border  approaches  that  of  the 
optic  disc,  and  the  ophthalmoscopic  appearance  is  scarcely  to  be 
distinguished  from  that  which  is  seen  when  ])ressure  excavation 
causes  atrophy  of  the  optic  nerve. 

Under  these  circumstances  the  other  diagnostic  signs  are  often 
wanting.  The  evidence  of  an  increased  tension  of  the  eye  may 
be  doubtful,  and  the  other  symptoms  due  to  increased  pressure 
are  then  frequently  absent.  Spontaneous  arterial  pulsation,  for 
instance,  occurs  where  the  increase  of  pressure  is  considerable  and 
rapid  ;  in  glaucoma  simplex  this  generally  fails,  and  the  fact  that 
this  phenomenon  can  easily  be  produced  by  slight  pressure  of  the 
finger  upon  the  eye  cannot  confirm  a  doubtful  diagnosis,  because 
in  this  respect  very  considerable  physiological  differences  exist. 
Very  frequently  under  absolutely  physiological  relations  a  slight 
pressure  of  the  finger  suffices  to  produce  the  arterial  pulsation. 

Frequently  the  fimctional  examination  clears  up  the  difficulty, 
since  under  these  circumstances  a  defect  appearing  first  in  the 
outer  half  of  the  visual  field  speaks  more  for  atrophy  of  the  optic 


GLAUCOMA   SIMPLEX.  507 

nerve.     In  otlier  eases  the  further  course  of  the  disease  furnishes 

♦ 

tlie  first  clue  to  the  real  nature  of  the  excavation,  since  either  the 
progressive  atrophy  or  the  increase  of  intraocular  pressure  will 
become  plainly  apparent. 

These  diagnostic  difficulties  are  increased  by  the  circumstance 
that  pressure  excavations  may  occur  in  eyes  in  which  an  increase 
of  tension  is  not  perceptible  to  touch. 

The  diagnosis  of  glaucoma  simplex  is  made  almost  alone  upon 
the  evidence  of  increased  intraocular  pressure  and  the  excavation 
of  the  optic  disc  dependent  upon  it.  If  the  increase  of  tension  be 
doubtful,  we  must  remember  that  for  the  reasons  above  stated 
the  ophthalmoscopic  examination  alone  does  not  always  furnish 
decisive  results. 

It  is  of  great  importance  in  such  cases  to  compare  the  two 
eyes.  Decided  physiological  excavation  is  almost  always  bilateral. 
Accordingly,  if  in  one  eye  the  optic  disc  present  a  flat  surface, 
while  in  the  other  it  is  excavated,  it  must  be  due  to  pressure ;  but 
in  such  a  case  one  would  not  fail  to  notice  a  difference  in  tension 
between  the  two  eyes. 

For  the  evidence  of  increased  tension  we  rely  principally  on  the 
sense  of  touch.  According  to  Coccius,  this  examination  is  best 
made  as  follows.  The  patient  is  directed  to  look  upward  while 
the  examiner  places  his  two  index  fingers  upon  the  sclera  below 
the  cornea,  and  then  tests  the  resistance  which  the  eye  offers  to  a 
slight  pressure.  Or  one  may  press  the  margin  of  the  under  lid 
upon  the  sclera  and  estimate  the  size  of  the  depression  thereby 
caused.  In  both  cases  we  endeavor  to  determine  the  degree  of 
force  necessary  in  order  to  produce  a  given  impression  upon  the 
eye. 

There  are  instruments  called  tonometers,  designed  to  measure 
exactly  the  force  necessary  to  produce  on  the  eyeball  a  depression 
of  known  and  measurable  depth ;  but  they  have  not  yet  been 
generally  adopted  in  practice,  for  reasons  not  necessary  here  to 
enumerate. 

Bowman*  has  proposed  to  indicate  the  normal  tension  of  the 
eye  as  determined  by  the  sense  of  touch  by  the  letter  T,  and  the 
degrees  of   increased  tension  by  +  Tj,  T^,  Tg,  and   the  degrees 

*  Ophth.  Hosp.  Eep.,  vol.  v.  1,  pag.  1. 


508  GLAUCOMA   SIMPLEX. 

of  decreased  tension  by — -Tj,  T^,  T3.  This  whole  scale  is  of 
course  simply  a  system  of  abbreviations  which  in  economy  of 
time  is  of  slight  value.  It  requires  only  a  little  more  time  and 
space,  but  is  much  more  comprehensible  to  the  general  under- 
standing, for  instance,  instead  of  "  +  T3,"  to  write  "  stone  hard," 
or  instead  of  "  +  Ti?"  to  write  ''  doubtful  increase  of  tension." 

If,  as  is  generally  the  case  in  glaucoma  simplex,  the  increase 
of  intraocular  pressure  develop  only  gradually,  and  if  in  conse- 
quence of  this  the  optic  disc  be  only  slowly  excavated,  the  press- 
ure excavation,  when  physiological  excavation  pre-existed,  may 
reach  a  considerable  depth  without  disturbing  vision. 

Finally,  however,  a  destruction  of  nervous  elements  is  sure 
to  occur.  For  the  nerve  fibres  whicii  pass  through  the  lamina 
cribrosa  are  compressed  simultaneously  with  it;  but  even  if  they 
escape  this  danger,  they  are  pressed  against  the  sharp  edge  of  the 
excavation  at  the  point  where  they  pass  over  into  the  retina.  The 
consequence  is  a  gradual  atrophy  of  the  nerve  fibres,  most  ap- 
parent at  the  margin  of  the  excavation.  Just  here,  where  the 
layer  of  nerve  fibres  should  be  thickest,  it  is  often  reduced  to  a 
minimum. 

Excavated  optic  discs  often  assume  for  this  reason  the  opaque 
white  color  characteristic  of  atrophic  degeneration.  In  the  retina 
there  follows,  as  the  invariable  consequence  of  this  condition,  an 
atrophy  of  the  nerve  fibres  and  ganglion  cells,  while  the  other 
retinal  elements  remain  unchanged. 

The  first  noticeable  eifect  of  this  process  upon  the  sight  is  a 
limitation  of  the  field  of  vision,  which  generally  begins  in  the 
inner  upper  or  inner  lower  quadrant,  and  extends  from  there  tOM'ard 
both  the  periphery  and  the  centre.  It  may  thus  gradually  assume 
a  concentric  form,  involving  the  inner  rather  more  than  the  outer 
half  of  the  field  of  vision,  so  that  by  a  simultaneous  reduction 
from  above  and  below  the  visual  field  is  reduced  to  a  small  hori- 
zontal or  inclined  stripe  whose  inner  limit  approaches  the  fixa- 
tion-point. Central  vision  is  often  for  a  long  time  not  interfered 
with  ;  indeed,  it  may  happen  that  with  a  high  degree  of  concen- 
tric limitation  of  the  field  of  vision  a  small  visual  field  with  a 
fair  degree  of  central  vision  remains.  Generally,  however,  the 
defect  spreads  from  the  inner  half  of  the  field  of  vision  as  far  as 
the  fixation-point,  causing  then  serious  disturbance  of  vision. 


INFLAMMATORY   GLAUCOMA.  509 

Glaucoma  simplex  may  in  this  way  cause  absolute  blindness 
without  the  occurrence  of  inflammatory  sym{)toms  or  any  incon- 
venience other  than  the  loss  of  vision.  The  eye  becomes  stone 
hard,  the  optic  disc  deeply  excavated,  and  generally  the  branches 
of  the  anterior  perforating  veins  running  in  the  conjunctiva  are 
dilated  by  mechanical  hyperemia.  Contraction  of  the  anterior 
chamber  and  sluggishness  of  the  iris  also  occur.  Other  externally 
visible  changes,  which  are  so  noticeable  in  inflammatory  glaucoma, 
for  instance,  clouding  of  the  cornea  and  dilatation  of  the  pupil,  do 
not  occur  in  glaucoma  simplex.  I  am  satisfied  that  all  cases  of 
glaudbma  M^hich  present  either  of  the  two  last-named  symptoms 
should  be  regarded  as  belonging  to  the  inflammatory  form,  even 
although  there  is  at  the  time  of  the  examination  no  pericorneal 
injection. 

The  course  of  the  disease  is  generally  very  tedious,  and  extends 
over  several  years;  it  is  only  exceptionally  that  glaucoma  sim- 
plex causes  blindness  in  a  shorter  time.  Both  eyes  are  generally 
affected. 

INFLAMMATORY    GLAUCOMA. 

Under  this  head  are  included  all  those  cases  in  the  course  of 
which  inflammatory  symptoms  occur.  They  form  the  great  ma- 
jority of  cases.  The  relative  frequency  of  the  two  forms  cannot 
be  exactly  stated.  Aside  from  the  possibility  above  referred  to,  of 
confounding  glaucoma  simplex  with  certain  changes  in  the  form 
of  the  optic  disc,  the  existing  statistical  examinations  disagree  con- 
siderably. Statistics*  showing  simply  the  condition  in  which  the 
patients  presented  themselves  for  treatment,  give  for  glaucoma 
without  inflammatory  symptoms  about  one-third  of  all  cases, 
while  HafFmans,f  among  82  eyes  which  were  absolutely  blinded 
by  glaucoma,  recognized  inflammatory  symptoms  73  times.  One 
may  assume  that  generally  an  increase  of  pressure  precedes  the 
appearance  of  inflammatory  symptoms;  indeed,  it  is  doubtful 
whether  glaucomatous  inflammation  ever  occurs  without  previous 
increase  of  pressure. 

*  Becker,  Bericht  dcr  Wiener  Augenklinik,  1867,  pag.  9;  Lucian  Eydel, 
Ueber  Glaucom,  ibid.,  pag.  135;  Laquer,  Etudes  cliniques  sur  le  Glaucoine, 
Annales  d'Oculi.stique,  1809,  Janvier  et  Fevrier,  pag.  33. 

t  Arch.  f.  Ophth.,  B.  viii.  2,  pag.  145. 


510  INFLAMMATORY   GLAUCOMA. 

Tlie  fact  that  in  glaucoma  simplex  the  eye  may  become  stone 
hard  without  inflammation,  shows  that  excessive  pressure  does  not 
of  necessity  cause  inflammation;  still,  it  is  very  probable  that  it 
will  do  so  if  the  increase  of  pressure  be  rapid.  A  case  reported 
by  L.  Rydel*  is  very  interesting  in  this  connection.  In  it,  rapid 
and  very  considerable  increase  of  pressure  was  observed  as  the 
precursor  of  very  severe  glaucomatous  inflammation. 

Nearly  all  the  symptoms  which  give  to  glaucomatous  inflamma- 
tion its  peculiar  character  may  be  referred  to  the  influence  of  a 
rapid  increase  of  intraocular  pressure.  It  causes  a  peculiar  appear- 
ance in  the  pericorneal  injection.  Not  only  is  there  hyperseiliia  of 
the  numerous  fine  arterial  vessels  which  radiate  about  the  margin 
of  the  cornea,  but  there  is  at  the  same  time,  and  in  a  still  higher 
degree,  a  decided  venous  hyperemia.  The  fine  venous  net-work 
surrounding  the  cornea,  which  in  the  normal  eye  is  scarcely  visi- 
ble, and  the  larger  branches,  part  of  which,  as  perforating  vessels, 
emerge  from  the  sclera,  are  excessively  and  uniformly  dilated. 
They  are  over-filled,  since  from  the  sudden  increase  of  pressure 
the  flow  of  blood  through  the  vena;  vorticosre  is  made  difficult. 

We  observe  similar  processes  in  the  ciliary  nerves.  They 
can  accommodate  themselves  to  a  gradual  increase  of  pressure, 
but  a  sudden  increase  causes  disturbances  in  both  the  sensitive 
and  the  motor  fibres. 

Among  these  are,  first,  those  severe  ciliary  neuralgias  which 
affect  not  only  the  eye,  but  principally  the  supra-orbital  region, 
and  often  the  entire  half  of  the  head.  Frequently  these  pains  are 
the  symptom  of  which  the  patients  complain  most,  and  this  fact 
may  lead  to  serious  diagnostic  errors.  A  false  diagnosis  may  still 
more  easily  be  made  when  simultaneously  severe  vomiting  occurs, 
which  distracts  the  attention  from  the  eyes  to  the  gastric  organs. 

Aside  from  these  pains,  symptoms  of  paralysis  appear  in  the 
sensitive  nerves  of  the  eye  itself.  A  part  or  the  whole  of  the  cor- 
nea loses  its  sensibility,  so  that  it  may  be  touched  wuth  the  finger 
without  any  symptoms  of  reaction.  That  in  these  cases  the  con- 
duction is  actually  interfered  with  by  the  pressure,  is  proved  by  the 
observation  of  Von  Graefe,t  that  immediately  after  the  puncture 
of  the  anterior  chamber  sensation  may  again  appear  in  the  cornea. 

*  L.  c,  pag.  140.  t  -^I'cli-  f-  Ophth.,  B.  i.  2,  pag.  305. 


INFLAMMATORY    GLAUCOMA.  511 

The  paralysis  of  the  motor  fibres  of  the  ciliary  nerves  is  made 
evident  by  the  dilatation  and  rigidity  of  the  pnpil,  and  the 
limitation  of  the  range  of  accommodation.  Mydriasis  is  a  very 
important  diagnostic  sign  of  inflammatory  glaucoma.  No  other 
inflammation  of  the  eye  causes  such  a  striking  spontaneous  dila- 
tation of  the  pupil. 

The  shallowness  of  the  anterior  cliAi^iber  also  shows  the  rapid 
progress  of  the  intraocular  pressure  which  characterizes  inflamma- 
tory glaucoma.  While  in  glaucoma  simplex  there  is  generally  an 
equilibrium  established  between  the  pressure  behind  and  that  in 
front  of  the  lens,  in  inflammatory  glaucoma  the  lens,  together  with 
the  iris,  is  forced  forward,  and  the  depth  of  the  anterior  chamber 
is  thereby  considerably  diminished. 

There  develops  simultaneously  a  cloudiness  of  the  refracting 
media.  The  most  striking  and  important  is  the  diifuse  cloudiness 
of  the  cornea,  which  may  be  easily  recognized  by  focal  illumina- 
tion. At  fiirst  it  is  uniformly  disseminated  over  the  entire  cornea, 
but  if  the  glaucomatous  inflammation  continue  uninterruptedly 
several  days,  dull  opacities  may  develop,  especially  in  the  deeper 
layers  of  the  cornea,  while,  if  the  inflammation  be  very  severe, 
numerous  small  irregularities  may  appear  upon  the  surface.  On 
the  contrary,  the  oft-reported  clouding  of  the  aqueous  humor  ap- 
pears to  me  very  doubtful.  If  the  cornea  be  clouded,  it  is  scarcely 
possible  to  form  an  opinion  whether  a  diffuse  cloudiness  exists 
either  in  the  aqueous  humor  or  in  the  deeper  media.  Coccius* 
found  the  aqueous  humor,  which  was  received  in  a  watch-crystal 
during  paracentesis,  frequently  of  a  yellow  color  but  not  clouded. 

The  case  is  the  same  with  the  diff'use  cloudiness  v/hicli  is  said 
fo  occur  in  the  vitreous  body.  Only  when  examined  through  a 
perfectly  clear  cornea  is  it  possible  to  determine  the  existence  of 
cloudiness  in  the  vitreous  body.  But  the  clouding  of  the  cornea 
is,  according  to  my  experience,  so  constant  and  so  early  an  occur- 
rence in  inflammator}^  glaucoma  that  I  have  never  been  able  to 
demonstrate  the  simultaneous  presence  of  cloudiness  in  the  vitreous 
body. 

If  the  general  fundus  of  the  eye  be  visible,  one  frequently 
observes  spontaneous  arterial  pulsation  during  the  inflammatory 

,  *  Arch.  f.  Ophth.,  B.  ix,  1,  pag.  19. 


512  INFIvAMMATORY   GLAUCOMA. 

attack,  whether  pressure  excavation  has  ah'eady  been  caused  or  not. 
It  may  disappear  in  the  course  of  a  few  hours,  and  then  reappear. 

The  disturbance  of  vision  associated  with  the  glaucomatous 
inflammatory  attacks  is  caused  partly  by  the  increase  of  the  intra- 
ocular pressure  paralyzing  the  optic-nerve  fibres,  either  in  the 
retina  itself  or  in  the  lamina  cribrosa,  and  partly  by  the  clouding 
of  the  cornea.  Finally,  it  may  to  some  extent  be  due  to  inter- 
ference with  retinal  circulation,  since  Donders  has  shown  that 
simultaneously  with  the  appearance  of  the  arterial  pidse  produced 
in  the  normal  eye  by  pressure  of  the  finger  on  the  side  of  the  eye- 
ball, the  field  of  vision  is  always  obscured. 

All  these  causes  together  may  induce  a  very  considerable  dimi- 
nution of  central  vision  without  any  simultaneous  contraction  of 
the  visual  field,  in  cases  where  the  glaucomatous  inflammation 
sets  in  without  the  previous  existence  of  a  pressure  excavation. 

Later,  of  course,  defects  in  the  visual  field  dcveloj)  in  these 
cases,  beginning  generally  in  the  upper  or  lower  median  quadrant. 

The  blindness  which  sooner  or  later  is  caused  by  inflammatory 
glaucoma  is  generally  attributed  to  the  optic-nerve  excavation  ; 
but  this  cannot  be  the  only  cause.  Cases  occur  in  which  inflam- 
matory glaucoma  causes  blindness  without  the  development  of 
any  excavation,  and  in  wliich  accordingly  the  lamina  cribrosa 
appears  to  possess  an  abnormal  capacity  for  resisting  the  increase 
of  intraocular  pressure.*  In  such  cases  the  optie  nerve  generally 
shows  signs  of  atrophic  degeneration.  We  may  assume  that  in 
these  cases  the  increase  of  intraocular  pressure  exerts  a  hurtful 
influence  upon  the  circulation  and  nutrition  of  the  inner  coats  of 
the  eye,  and  that  blindness  is  caused  by  the  ischsemic  paralysis  of 
the  retina  or  by  a  simultaneous  disturbance  of  its  nutrition  (soft- 
ening?). 

Among  the  subjective  symptoms  which  frequently  occur  in 
inflammatory  glaucoma  is  first  to  be  mentioned  the  appearance  of 
a  halo  surrounding  the  flame  of  a  light.  The  outer  margin  of 
this  halo  is  red,  the  inner  margin  blue-green,  and  between  are 
the  ordinary  prismatic  colors.     Dondersf  explained  this  phenom- 

*  Conip.  Mauthner,  Lehrbuch  der  Oplitlialmoscopie,  pag.  281  ;  A.  v. 
Graefe,  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  232;  L.  Kydel,  Arch.  f.  Ophth.,  B. 
xviii.  1,  pag.  1. 

t  Arch.  f.  Ophth.,  B.  viii.  2,  pag.  165. 


INFLAMMATORY   GLAUCOMA.  513 

enon  as  a  refraction  in  the  lens,  which  can  occur  entirely  inde- 
pendent of  glaucoma  whenever  the  pupil  is  somewhat  wider  than 
usual.  The  phenomenon  does  not  occur  in  glaucoma  simplex 
where  the  refracting  media  remain  unchanged  and  the  pupil  is 
not  dilated.  That  it  occurs  more  frequently  in  inflammatory 
glaucoma  appears  to  depend  partly  upon  the  dilatation  of  the 
pupil,  partly  also  perhaps  upon  a  change  in  the  lens,  but  princi- 
pally upon  the  clouding  of  the  cornea,  which  accompanies  the 
attacks  of  glaucoma.  This  phenomenon  can  be  very  easily  illus- 
trated by  observing  the  flame  of  a  candle  through  a  glass  strewed 
with  lycopodium  powder. 

The  prominent  subjective  light  and  color  symptoms  which 
accompany  severe  inflammatory  attacks  are  probably  to  be  re- 
garded as  the  consequences  of  the  rapid  increase  of  the  intraocular 
pressure. 

In  the  majority  of  cases  the  glaucomatous  attacks  are  at  first 
very  mild,  pass  quickl}^  fiway,  and  are  separated  by  an  interval, 
during  which  a  reduction  of  the  range  of  accommodation  and  an 
evident  increase  of  tension  are  the  only  abnormal  symptoms. 
The  individual  attacks  are  characterized  in  their  mild  forms  by 
increase  of  tension,  paresis  of  accommodation,  slight  sluggishness 
and  dilatation  of  the  pupil,  diffuse  clouding  of  the  cornea,  hy- 
persemia  of  the  retinal  veins,  the  perception  of  halos,  and  an 
irregular  obscurity  of  vision,  so  that  everything  appears  to  the 
patient  as  if  in  a  cloud  or  as  if  thick  smoke  swept  before  the  eyes. 
In  more  severe  attacks  there  are  added  to  these  symptoms  flatten- 
ing of  the  anterior  chamber,  indistinctness  of  eccentric  vision, 
arterial  pulsation,  and  even  peripheral  defect  in  the  field  of  vision, 
especially  by  weak  illumination. 

Von  Graefe  called  this  condition  the  prodromal  stage  of  glau- 
coma. Evidently  the  condition  is  one  of  periodically  occurring 
rapid  increase  of  intraocular  pressure  already  complicated  with 
inflammatory  symptoms. 

Later,  the  inflammatory  attacks  become  more  frequent,  often 
occurring  in  a  distinctly  intermittent  manner.  The  inflammatory 
symptoms  also  assume  a  more  acute  character,  are  protracted  after 
the  remission  of  the  most  severe  symptoms,  so  that  there  develops 
a  condition  of  chronic  inflammation  (glaucoma  chronicum)  with 
more  or  less  severe  exacerbations,  which   finally,   by  increasing 


514  IIS'PLAMMATORY   GLAUCOMA. 

excavation  of  the  optic  nerve  and  loss  of  central  vision,  causes 
blindness. 

Severe  glaucomatous  inflammation  may  run  this  course  in  a 
very  few  weeks  (glaucoma  acutum);  indeed,  it  sometimes  happens 
that  absolute  blindness  occurs  in  the  course  of  a  few  days  or  even 
hours.  Such  cases,  already  mentioned  by  Mackenzie,*  have  been 
designated  bv  Von  Graefe  as  ^-laucoma  fulminans. 

The  glaucomatous  process  may  continue^and  cause  great  patho- 
loo;ical  cliano;es,  even  after  absolute  destruction  of  vision.  Tlie 
iris  becomes  reduced  to  a  narrow  band,  the  pupillary  margin  is 
everted  forward,  so  that  a  black  ring  of  the  uveal  surface  becomes 
visible,  the  lens  becomes  cataractous  and  swollen,  the  cornea  is 
greatly  clouded,  and  often  partially  breaks  down,  hemorrhages 
occur  into  the  anterior  chamber,  into  the  vitreous  body,  and  in  the 
parenchyma  of  the  inner  membranes.  The  sclera  finally  yields 
to  the  steadily  increasing  intraocular  pressure,  so  that  staphylomas 
develop  especially  upon  the  anterior  part  of  the  eyeball.  Even 
purulent  inflammation  may  occur  and  cause  atrophy  of  the  eyeball. 

It  should,  however,  be  specially  mentioned  that  this  is  not 
the  only  way  in  which  a  glaucomatous  eye  may  finally  become 
atrophied.  In  a  certain  class  of  cases  the  eye  after  repeated 
inflammatory  attacks  becomes  gradually  softer,  and,  yielding  to 
the  pressure  of  the  recti  muscles,  assumes  a  roundish,  cuboidal 
form.  All  painful  attacks  then  generally  cease,  and  finally  the 
eye  shrinks  to  a  very  small  stiwnp.  This  process  depends  upon 
inflximmatory  detachment  of  the  retina.  Arltf  was  the  first  to 
demonstrate  anatomically  that  as  a  general  thing  detachment  of 
the  retina  finally  occurs  in  glaucomatous  eyes.  Tliis  statement  has 
been  very  unreasonably  doubted  ;  but  its  truth  has  been  fully  con- 
firmed by  later  investigations.  Arn.  PagenstecherJ  found  detach- 
ment of  the  retina,  together  with  considerable  excavation  of  the 
optic  nerve,  in  a  subject  who  two  years  before  death  had  been 
blinded  by  glaucoma.  I  examined§  a  case  in  which  an  eye  had 
been  blinded  by  repeated  glaucomatous  inflammations,  and  which, 
during  a  new  and  severe  attack;  was  extirpated  by  Von  Graefe. 

*  Practical  Treatise,  London,  1854,  pag.  570. 
t  Augenheilkunde,  1856,  B.  ii.  pag.  IGl. 
X  Arch.  f.  Ophth.,  B.  vii.  1,  pag.  02. 
§  Ibid.,  B.  ix.  1,  pag.  199. 


ETIOLOGY   OF   GLAUCOMA.  515 

The  dissection  showed  a  recent  detachment  of  the  retina,  together 
with  a  deep  pressure  excavation. 

It  has  been  shown  that  detachment  of  the  retina  may  occur 
during  the  later  inflammatory  attacks,  and  may  then  be  the  cauSe 
of  atrophy  of  the  eye. 

The  time  of  life  is  the  most  important  element  in  the  etiology 
of  glaucoma.  It  -occurs  very  rarely  before  the  thirtieth  year. 
From  this  limit  the  predisposition  is  in  direct  proportion  to  the 
age.  It  is  more  frequent  in  the  female  than  in.  the  male  sex.  A 
predisposition  to  the  disease  may  be  inherited,  and,  according  to 
Von  Graefe,*  this  is  especially  true  of  the  inflammatory  forms. 

The  condition  of  refraction  exercises  a  decided  influence.  Glau- 
coma rarely  occurs  in  myopic  eyes,  and  in  these  rare  cases  it  is 
generally  of  the  simple  form.  Hypermetropia  exists  in  the  ma- 
jority of  cases,  and  the  question  naturally  arises,  whether  this  is  to 
be  regarded  as  a  cause  or  as  a  consequence  of  the  disease.  It  may 
be  that  the  influence  which  the  increased  intraocular  pressure 
exercises  upon  the  form  of  the  eye  flattens  the  cornea  and  thereby 
causes  hypermetropia.  But  neither  Dondersf  nor  Coccius|  could 
by  ophthalmometric  measurement  demonstrate  any  such  eflect 
upon  the  curvature  of  the  cornea,  and  we  may  therefore  assume 
that  the  attenuated  sclera  of  myopic  eyes  yields  more  easily  to  an 
intraocular  pressure,  while  in  emmetropic  and  hypermetropic  eyes 
this  j^ressure  affects  rather  the  optic  nerve  than  the  sclera. 

It  is  probable  that  the  rigidity  of  the  sclera,  which  so  often 
occurs  in  old  age,  favors  the  occurrence  of  glaucoma.  Whether 
fatty  degeneration  of  the  sclera,  which  was  observed  by  Coccius§ 
in  one  case,  can  be  regarded  as  a  cause  of  glaucoma,  is  doubtful. 
Instead  of  being  more  resisting,  fatty  degenerated  organs  are  gen- 
erally more  yielding.  Moreover,  a  deposit  of  the  phosphate  of 
lime  in  the  sclera  is,  according  to  Donders,||  a  frequent  occurrence 
in  old  age,  and  may  easily  be  mistaken  for  fatty  degeneration. 

*  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  228. 
t  Ibid.,  B.  viii.  2,  pag.  163. 

X  Die  Hcilanstalt  fiii-  Aiigenkrankc  zu  Leipzig,  1870,  pag.  o6,  and  Ophthal- 
mometrie  und  Spannungsmessung  am  kranken  Auge,  Leij)zig,  1872,  pag.  44. 

I  Arch.  f.  Ophth.,  B.  ix.  1,  pag.  21. 

II  Ibid.,  B.  ix.  2,  pag.  217. 


516  SECOXDAEY    GLAUCOMA.* 

The  attack  of  glaucomatous  i  n  flam  mat  iou  is  favored  principally 
by  mental  emotion  and  loss  of  sleep. 

Nearly  all  ophthalmologists  have  observed  cases  in  which  glau- 
coma came  on  soon  after  the  use  of  atropine.  It  is  possible  that 
this  is  due  to  something  more  than  accident;  still,  in  a  somewhat 
limited  series  of  experiments  which  I  have  made  in  the  use  of 
atropine  in  glaucoma  simplex,  the  result  has  been  negative;  no 
inflammatory  symptoms  were  produced. 

SECONDARY   GLAUCOJIA. 

Certain  other  pathological  processes  may  become  complicated 
with  glaucomatous  intraocular  pressure  and  its  consequences. 
Among  the  diseases  of  the  cornea  are  first  to  be  mentioned  those 
staphylomatous  cicatrices  with  which  the  iris  has  formed  adhesions 
(staphyloma  partiale  and  totale).  Iritis,  Avith  complete  annular 
attachment  of  the  pupillary  margin,  may  also  cause  glaucomatous 
blindness. 

Moreover,  the  luxation  of  the  lens,  or  its  expansion  in  traumatic 
cataract  or  in  discision,  may  produce  glaucomatous  intraocular 
pressure. 

Moreover,  retinal  hemorrhages,  which  at  first  differ  in  no  way 
from  other  forms  of  this  disease,  play  an  important  role.  Gradu- 
ally, however,  in  the  course  of  some  months,  an  increase  of  ten- 
sion occurs  ;  glaucomatous  inflammation  develops,  generally  with 
severe  ciliary  neuralgia,  and  vision  which  had  already  been  seri- 
ously affected  is  absolutely  destroyed. 

Finally,  certain  cases  should  here  be  mentioned  in  which  Hor- 
ner* demonstrated  a  severe  neuralgia  of  the  fifth  nerve  to  be  the 
cause  of  a  somewhat  abnormally  progressing  glaucoma. 

These  cases  of  secondary  glaucoma  are,  however,  frequent  enough, 
or  are  sufficiently  characterized  by  their  anomalous  course,  to  justify 
the  assumption  of  a  connection  between  the  glaucoma  and  the  pre- 
existing disease.  In  other  cases,  on  the  contrary,  the  occurrence  of 
glaucoma  with  other  affections  of  the  eye  is  to  be  regarded  simply 
as  an  accidental  complication.  Among  such  cases  belongs,  for  in- 
stance, glaucoma  with  senile  cataract  or  with  aphakia.  Glaucoma 
may  also  occur  as  an  accidental  complication  simultaneously  M'ith 


1 


*  Arch.  f.  Ophth  ,  B.  xii.  2,  pag.  1. 


IRIDECTOMY   IN   GLAUCOMA.  517 

amblyopia,  due  to  extraocular  causes,  or  together  with  choroiditis, 
retinitis,  etc.  It  is  especially  interesting,  too,  that  glaucoma  may 
develop  with  pre-existing  detachment  of  the  retina.* 

TREATMENT. 

To  Von  Graefe  undying  gratitude  is  due  for  introducing  iridec- 
tomy in  the  treatment  of  glaucoma,  and  thus  greatly  diminishing 
the  number  of  those  who  formerly  fell  victims  to  this  disease. 

Besides  iridectomy,  scarcely  any  other  treatment  is  of  the  least 
avail.  Opiates  or  morphine  injections  may  perhaps  modify  an 
existing  nervous  excitement,  or  even  help  to  relieve  slight  inflam- 
matory attacks ;  their  effects,  however,  are  only  palliative. 

Paracentesis  of  the  anterior  chamber  causes  a  temporary  dimi- 
nution of  the  pressure,  but,  even  though  frequently  repeated,  does 
not  prevent  the  further  development  of  the  disease. 

Only  iridectomy  causes  a  permanent  diminution  of  the  glauco- 
matous pressure.  To  accomplish  this  object  it  must  be  broad  and 
peripheral :  the  original  idea,  however,  that  by  this  method  the  iris 
was  excised  up  to  its  ciliary  margin  has  been  proved  to  be  an  error. 
Be  the  iridectomy  as  peripheral  as  possible,  the  inner  wound  wuU 
still  always  be  in  the  cornea, — that  is,  anterior  to  the  circumference 
of  the  membrane  of  Descemet, — and  even  when  the  iris  is  excised 
close  to  the  exterior  wound,  a  narrow  border  will  always  remain 
attached  to  the  ciliary  body.  Nevertheless,  the  iridectomy  should 
be  made  so  far  in  the  periphery  that,  upon  ophthalmoscopic  exam- 
ination, the  equator  of  the  lens  and  the  zonular  space,  exterior  to 
it,  can  be  distinctly  seen. 

The  place  of  the  iridectomy  is  so  to  be  chosen  that  the  diffusion 
of  light  dependent  upon  the  enlargement  of  the  pupil  may  be  re- 
duced as  much  as  possible.  Bowman  recommends  to  make  the 
iridectomy  above,  in  order  that  it  may  be  covered  by  the  upper 
lid.  Arlt  is  in  favor  of  the  iridectomy  below,  because  patients 
very  soon  learn,  by  raising  the  lower  lid,  to  cover  the  coloboma, 
especially  in  the  downward  direction  of  vision  usual  when  work- 
ing. Both  methods  possess  the  advantage  of  enabling  the  operator 
more  easily  to  excise  the  iris.  Certainly  the  iridectomy  either 
outward  or  inward  is  least  to  be  recommended. 

*  Haft'mans,  Bijdrage  tot  de  keniiis  van  het  glaucoma,  Utrecht,  1861,  Fall  iv. 


518  IRIDECTOMY    IX   GLAUCOMA. 

The  curative  effect  of  the  operation  is  best  sliown  in  recent  acute 
cases  of  inflammatory  glaucoma  which  have  occurred  in  individ- 
uals whose  vision  was  previously  good.  The  obstruction  of  the 
circulation  in  the  retina,  the  paralysis  of  the  nerve  fibres,  and  all 
the  disturbances  of  vision  depending  upon  it,  generally  disappear 
immediately  after  the  iridectomy.  The  clouding  of  the  cornea 
disappears  either  immediately  or  in  the  course  of  a  few  days, 
according  to  its  intensity.  Ecchymoses  of  the  retina  often  occur 
after  iridectomy  in  inflammatory  glaucoma,  but  unless,  unfortu- 
nately, they  occupy  the  region  of  the  macula  lutea,  they  do  not 
greatly  disturb  vision,  and  in  the  course  of  a  few  weeks  they  are 
re-absorbed. 

In  reference  to  the  prognosis,  the  earlier  the  operation  and  the 
fewer  the  permanent  changes  which  have  already  taken  place  the 
better  the  result  which  may  be  expected.  In  recent  cases,  even 
with  great  diminution  of  vision,  but  with  normal  or  only  slightly 
contracted  field  of  vision,  a  perfect  recov^ery  may  be  predicted  as 
the  result  of  the  operation ;  but  in  the  later  stages,  where  a  pressure 
excavation  has  ah'eady  been  formed  and  the  visual  field  has  be- 
come considerably  contracted,  no  more  can  be  ex})ectcd  than  to 
preserve  the  status  quo.  Occasionally,  however,  even  under  such 
circumstances,  unexpectedly  good  results  follow  iridectomy. 

If  sight  be  already  lost,  on  reduced  to  a  very  small  eccentric 
field  of  vision,  nothing  can  be  expected  from  an  operation.  The 
only  exceptions  to  this  are  those  rare  cases  of  acute  inflammatory 
glaucoma  which  in  the  course  of  a  few  hours  cause  blindness.  In 
one  such  case,  in  which  only  a  very  slight  perception  of  light  re- 
mained, but  in  which  iridectomy  was  performed  on  the  day  when 
the  blindness  occurred.  Von  Graefe  obtained  distinct  vision  and  a 
normal  field.* 

If  absokite  blindness  have  already  existed  for  a  considerable  time, 
or  if  it  have  come  on  gradually,  the  operation  can  be  indicated  only 
by  the  persistence  of  the  severe  ciliary  pains;  still,  in  the  later 
stages  of  the  disease  their  relief  by  an  operation  cannot  be  certainly 
relied  on. 

In  glaucoma  simplex  the  results  of  iridectomy  are,  on  the  whole, 
less  satisfactory.     The  disturbances  of  vision  are  here  principally 


*  Arch.  f.  Ophth.,  B.  viii.  2,  pag.  246. 


IRIDECTOMY   IN   GLAUCOMA.  519. 

to  be  referred  to  the  atropliy  of  the  nerve  fibres  caused  by  the  ex- 
cavation. The  iridectomy,  of  course,  cannot  improve  their  condi- 
tion, and  in  the  best  cases  the  most  that  can  be  expected  from  it  is 
to  preserve  the  status  quo.  The  value  of  iridectomy  in  glaucoma 
simplex  is,  of  course,  essentially  influenced  by  the  circumstances  of 
the  particular  case.  In  any  affection  of  the  optic  nerve  in  which  a 
pre-existing  physiological  excavation  becomes  so  widened  and  deep- 
ened that  it  is  liable  to  be  confounded  with  a  pressure  excavation, 
the  iridectomy  at  least  does  no  harm.  It,  moreover,  sometimes 
happens  that  cases  of  inflammatory  glaucoma  at  the  time  when 
the  iridectomy  is  undertaken  present  no  longer  any  evidence  of 
existing  inflammation,  and  the  operation  may  then  give  an  unex- 
pectedly good  result.  But  such  cases  are  not  glaucoma  simplex. 
Most  of  those  cases  in  which  iridectomy  does  harm  or  is  imme- 
diately destructive  are  those  with  undoubted  increased  tension  and 
pressure  excavation,  with  dilatation  of  the  anterior  perforating 
veins,  but  without  clouding  of  the  cornea,  dilatation  of  the  pupil, 
or  pain,  and  without  occasional  obscurity  or  clouding  of  the  field 
of  vision,  having  a  slow,  uninterrupted,  uniform  course,  and  which, 
beginning  with  a  limitation  upon  the  median  periphery,  go  on  to 
blindness.     Such  cases  we  call  glaucoma  simplex. 

There  is  no  objection  to  calling  these  cases  glaucoma  malignum, 
but  it  should  not  be  forgotten  that  we  are  not  able  to  predict  this 
malignity  with  that  certainty  which  is  desirable. 

After  the  iridectomy  the  position  of  affairs  soon  becomes  clear. 
The  eye  remains  stone  hard,  and  in  the  course  of  the  first  twenty- 
four  hours  pains  occur,  with  copious  lachrymation,  pericorneal  in- 
jection, and  clouding  of  the  cornea.  One  often  sees,  also,  slight 
hemorrhages  in  the  iris.  The  iris  and  the  lens  appear  forcibly 
pressed  against  the  inner  surface  of  the  cornea;  the  anterior  cham- 
ber remains  empty,  and  vision  is  soon  lost.  One  or  two  months 
generally  pass  away  before  the  inflammation  runs  its  full  course, 
but  even  then  the  anterior  chamber  does  not  fill,  or  at  least  only 
partially.  This  delayed  refilling  of  the  anterior  chamber  is,  more- 
over, not  the  cause  of  the  inflammatory  symptoms,  for  in  glaucoma 
simplex,  and  often  also  in  inflammatory  glaucoma,  one  sees  the 
anterior  chamber  remain  empty  without  the  appearance  of  inflam- 
mation or  any  other  bad  symptoms. 

The  female  sex  appears  much  more  disposed  to  malignant  glau- 


520  IRIDECTOMY  IN  glauco:n[a. 

coma  than  the  male.  The  cases  which  I  have  observed  have  been 
those  of  patients  in  whom,  shortly  before  or  in  the  beginning  of 
the  climacteric  years,  glaucoma  simplex  had  developed  in  one  eve, 
Avhile  in  the  other  there  Avas  no  apparent  increase  of  pressure.  In 
general,  when  the  disposition  to  malignant  glaucoma  exists,  it  is 
for  both  eyes.  Yon  Graefe's*  statement  that,  at  most,  two  per 
cent,  of  the  cases  operated  on  for  glaucoma  simplex  run  a  malig- 
nant course,  is  surely  based  upon  too  low  an  estimate. 

The  result  of  iridectomy  is  generally  unfavorable  in  those  cases 
of  secondary  glaucoma  which  have  developed  after  retinal  hemor- 
rhages. In  such  cases  vision  is  frequently  greatly  impaired  by  the 
hemorrhages,  and  is  irrevocably  lost  by  the  glaucomatous  disease. 
But  if  severe  and  continuous  pains  remain  which  yield  to  no 
other  treatment,  nothing  can  be  expected  from  iridectomy,  and  it 
only  remains  to  enucleate  the  eye.  Still,  these  cases  may  end  in 
atrophy  and  entire  rest  of  the  eye. 

In  the  great  majority  of  cases  the  cure  caused  by  iridectomy  is 
permanent.  It  is  only  exceptionally  that  an  increase  of  ])ressure 
gradually  returns  and  detracts  from  the  good  result  which  had 
been  obtained.  This  appears  especially  to  happen  in  cases  which 
have  run  a  chronic  course,  or  where  the  operation  has  not  been 
skilfully  performed,  for  instance,  where  the  iridectomy  has  not 
been  made  near  enough  to  the  j)eriphery  or  is  too  small,  or  where 
the  iris  has  not  been  properly  replaced,  but  has  remained  fastened 
to  the  wound.  Under  these  circumstances  a  second  iridectomy, 
diametrically  opposite  the  first,  is  indicated. 

In  the  later  stages  of  glaucoma,  and  very  seldom  also  in  cases 
which  are  operated  upon  early  and  under  otherwise  favorable 
circumstances,  the  effect  of  the  iridectomy  is  gradually  diminished 
by  the  foct  that  the  process  of  atrophy  of  the  nerve  fibres  in  the 
excavation  makes  still  further  progress.  This  is  partly  the  reason 
why  operations  which  have  been  delayed  until  the  field  of  vision 
is  greatly  reduced  and  central  vision  diminished,  cannot  always 
with  certainty  be  relied  upon  to  preserve  the  status  quo. 

In  a  considerable  number  of  cases  there  forms  upon  the  place  of 
the  operation  a  peculiar  cicatrix,  which  Von  Graefef  has  described 

*  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  205. 
t  Ibid.,  B.  viii.  2,  pag.  263. 


\ 


IRIDECTOMY    IN    GLAUCOMA.  521 

as  cystoid  cicatrization.  The  lips  of  the  wound  separate  from  each 
other,  bands  of  tough  cicatricial  tissue  stretch  across  the  wodnd, 
and  the  space  between  them  is  closed  by  a  transparent  membranous 
substance.  Occasionally  this  thin  membrane  is  broken,  and  the 
aqueous  humor,  exuding  under  the  conjunctiva,  forms  there  a 
vesicular  prominence.  In  slight  cases  of  cystoid  cicatrization 
there  generally  occurs  a  thickening  of  this  membranous  tissue, 
and  the  wound  assumes  nearly  its  proper  appearance.  In  extreme 
cases  the  condition  remains  a  long  time  unchanged,  and  may  be- 
come the  starting-point  of  irritations,  which,  when  neglected,  may, 
by  purulent  inflammation,  hypopion,  and  secondary  iritis,  bring 
the  eye  into  great  danger  or  even  destroy  it  by  panophthalmia. 
This  peculiar  form  of  cicatrization  appears  to  be  caused  by  the 
anatomical  relations  of  the  sclera.  It  is  occasionally  also  seen 
after  peripheral  linear  extraction,  while  it  does  not  occur  in  clean 
corneal  wounds.  On  the  other  hand,  it  is  certain  tliat  the  increase 
of  pressure  has  a  causative  effect,  since  in  other  non-glaucomatous 
cases  this  kind  of  cicatrization  after  iridectomy  occurs  only  very 
exceptionally. 

The  theory  of  the  operation  of  iridectomy  cannot  as  yet 
be  explained.  Even  in  normal  eyes  it  is  said  to  cause  a  per- 
manent diminution  of  the  intraocular  pressure.  At  least  Von 
Hippel  and  Griinhagen*  were  able  to  demonstrate,  by  mano- 
metric  measurement,  a  diminution  of  the  intraocular  pressure, 
in  rabbits,  cats,  and  dogs,  from  Avhom,  in  the  course  of  several 
months,  by  repeated  operations,  a  considerable  part  of  the  iris 
had  been  removed.  But  the  explanation  of  this  as  well  as  of 
the  therapeutic  effect  of  iridectomy  in  glaucoma  is  still  wanting. 
There  seems  to  be  the  necessity  for  assuming  that  it  exercises 
some  mechanical  influence,  and  yet  the  proof  of  this  has  thus  far 
never  been  adduced.  That  the  coloboma  of  the  iris  is  of  itself 
not  essential  is  self-evident,  and  it  would  be  superfluous  to  cite 
a  case  reported  by  Haflfmans  of  glaucoma  with  congenital  colo- 
boma iridis.  A^on  Graefe  also  saw  glaucoma  with  congenital 
irideremia. 

Von  Graefe  seemed  inclined  at  first  to  lay  weight  upon  the 
diminution  of  the  secreting  surface;  but  it  is  not  so  much  a  ques- 


*  Arch.  f.  Opth.,  B.  xvi.  pag.  43. 
34 


522  IRIDECTOMY   IN   GLAUCOMA. 

tion  of  the  extent  of  the  secreting  surface  as  of  the  pressure  which 
determines  the  secretion. 

Bowman  entertained  the  idea  that  the  vitreous  fluid  could  pass 
through  the  zonula  Zinnii  into  the  anterior  chamber,  and  thence 
escape  through  the  cornea.  On  this  theory  the  zonula  should  be 
exposed  by  a  periplieral  iridectomy,  and  thus  this  escape  of  vitre- 
ous substance  made  easy.  But  the  occurrence  of  glaucoma  in 
connection  with  aphakia  proves  that  the  freest  possible  communi- 
cation between  the  vitreous  and  the  anterior  chamber  guarantees 
no  protection. 

According  to  Donders,*  glaucoma  is  to  be  regarded  as  a  neuro- 
sis of  the  nerves  governing  the  secretion  of  the  eye,  generally  ex- 
cited as  a  reflex  neurosis  of  the  iris,  or  at  least  maintained  and 
aggravated  by  consequent  tension  upon  it.  The  iridectomy  cures 
the  glaucoma,  because  it  relieves  tlie  irritation  of  the  overstrained 
nerves  of  the  iris.  This  theory,  however,  does  not  hold  good  for 
all  cases.  With  aphakia,  for  instance,  or  even  in  glaucoma  sim- 
plex, a  tension  of  the  iris  cannot  be  regarded  as  the  cause  for  the 
continuance  of  the  glaucoma,  and  even  in  the  inflammatory  form 
no  such  tension  can  be  demonstrated.  When  in  such  a  condition 
the  deptli  of  tl^e  anterior  chamber  is  diminished,  and  the  iris  is 
driven  forward,  it  is  also  always  paralyzed,  and  the  pupil  in 
consequence  of  this  is  dilated. 

Stelhvag  finally  has  advanced  the  view  that  not  the  iridectomy, 
but  the  wound  necessarily  made  in  performing  it,  is  the  essential 
element.  He  asserts  that  the  wound  heals  not  by  direct  adhesion 
of  its  edges,  but  by  the  formation  of  a  connective-tissue  cicatrix, 
and  thereby  it  becomes  possible  for  the  sclerotic  to  yield  some- 
what to  an  increase  of  intraocular  pressure.  These  suppositions 
are  certainly,  to  some  extent,  open  to  criticism.  Even  when  the 
incision  is  made  as  far  as  possible  in.  the  periphery,  only  a  very 
small  part  of  the  wound  lies  in  the  sclera.  The  greater  part  is 
in  the  cornea,  and  in  the  normal  course  of  healing  there  is  in 
these  wounds,  as  I  have  satisfied  myself  by  anatomical  exam- 
ination, no  deposit  of  new-formed  tissue,  but  immediate  union. 
Moreover,  scar  tissue  is  generally  regarded  not  as  more  yielding, 
but,  on  the  contrary,  as  less  so  than  normal  tissue. 

*  Klin.  Monalsbl.  f.  Augenheilk.,  1803,  jmg.  503. 


lEIDECTOMY   IN   GLAUCOMA.  523 

Exner*  has  satisfied  himself  by  the  examination  of  injected 
albino  eyes  of  dogs  and  rabbits,  on  which  iridectomy  had  been 
performed  from  two  to  four  weeks  previously,  that  almost  always 
anastomoses  could  be  demonstrated,  which,  at  the  place  of  the 
operation  in  the  iris,  connected  the  arteries  with  the  veins,  so  that 
arterial  blood,  without  having  to  pass  through  a  capillary  system, 
streamed  immediately  into  the  veins.  The  substitution  of  these 
wide  anastomoses  for  the  narrow  capillary  vessels  diminishes  not 
only  the  pressure  in  the  stump  of  the  artery  which  had  supplied  the 
excised  portion  of  the  iris  with  blood,  but  also  the  pressure  in  the 
entire  circ.  art.  iridis  major  and  in  the  arterial  vessels  of  the  cho- 
roid in  general.  Exner  lays  weight  upon  the  fact  that  the  margin 
of  the  iris  remaining  after  iridectomy  is  broader  than  seems  to  be 
generally  supposed,  and  that  room  is  thus  given  for  the  formation 
of  anastomoses  in  the  iris  tissue.  This  cannot  take  place  when, 
during  the  operation,  as  often  accidentally  happens,  the  iris  is 
torn  away  from  the  ciliary  body  (iridodialysis),  without  lessening 
the  effect  of  the  iridectomy  as  regards  the  reduction  of  intraocular 
pressure. 

*  65.  Band  der  Sitzungsberichte  der  k.  k.  Akademie  der  Wissenschaften, 
Mai,  1872,  und  Medic.  Jahrbiicher  der  Geseilsoh.  der  Wiener  Aerzte,  1873, 
Heft  i.  pag.  52. 


ESSENTIAL  PHTHISIS  OF  THE  EYEBALL. 


Quite  as  mysterious  as  the  glaucomatous  increase  of  intraocular 
I)ressure  are  certain  cases  where  the  pressure  decreases.  Von 
Graefe,*  in  order  to  distinguish  this  from  the  ordinary  form  of 
atrophy  of  the  eyeball,  caused  by  irido-cyclitis  or  irido-choroiditis, 
has  called  it  essential  phthisis. 

Only  very  few  cases  have  been  observed,  but  all  of  these  had 
been  preceded  by  injuries. 

In  the  case  described  by  Von  Graefe,  the  patient,  ten  years 
previously,  had  received  an  injury  at  the  inner  angle  of  the  eye, 
and  had  suffered  since  then  by  occasional  irritability  of  the  eye 
from  the  effect  of  light,  with  excessive  lachrymation,  and  severe 
pain  in  the  eye  and  in  its  neighborhood.  The  eye  was  exceedingly 
soft,  and  its  form  altered  apparently  by  the  pressure  of  the  recti 
muscles.  The  cornea,  especially  when  the  patient  was  exposed  for 
a  long  time  to  tlie  light,  was  surrounded  by  a  slightly  injected 
zone,  and,  moreover,  in  its  deeper  parts  a  number  of  fine  gray, 
irregular,  sinuous  opacities  could  be  seen,  which  Von  Graefe 
regarded  as  the  optical  expression  of  folds  or  ^vrinkles  in  the 
membrane  of  Descemet.  During  the  attacks,  vision  was  reduced 
to  ^,  and  by  means  of  the  stenopaic  apparatus  could  be  improved 
to  I.  The  attacks  lasted  several  hours,  and  in  the  free  intervals 
the  eye  was  normal,  showing  only  a  very  slight  diminution  of 
vision  and  tension. 

Swanzyt  observed  similar  variations  in  the  resistance  of  the 
eye,  with  greater  or  less  diminution  of  the  intraocular  pressure, 
developed  after  a  jDrolapse  of  the  vitreous  body  accompanying  a 
peripheral  linear  extraction.  The  irritability,  lachrymation,  peri- 
corneal injection,  ciliary  neuralgia,  subjective  light  symptoms,  etc., 
which  accompanied  the  diminution  of  pressure,  were  sometimes 


*  Arch.  f.  Ophth.,  B.  xii.  2,  pag.  256. 

f  Dublin  Quarterly  Journal,  1869,  Nov.,  pag.  531 ;  Annales  d'Oculistique, 
1870,  Nov.  ct  Dec,  pag.  212. 
524 


ESSENTIAL    PHTHISIS.  525 

slight  and  sometimes  excessive.  The  cornea  showed  no  changes. 
In  the  beginning  of  the  affection  a  slight  hemorrhage  was  observed 
in  the  anterior  chamber,  together  with  clouding  of  the  vitreous, 
which  was  likewise  probably  of  a  hemorrhagic  nature. 

In  a  case  observed  by  Nagel*  there  developed,  after  an  operation 
for  strabismus  convergens,  a  diminution  of  the  consistency  of  the 
eye,  with  great  photophobia  and  hypersecretion  of  tears.  After  this 
condition  had  continued  some  time,  the  normal  tension  gradually 
reappeared.  The  cornea  showed  changes  similar  to  those  in 
Von  Graefe's  case:  still,  Nagel  regarded  the  anterior  corneal  sur- 
face as  the  seat  of  the  affection.  The  eye  had  been  previously 
amblyopic. 

Finally,  in  a  case  observed  by  me,  a  contusion  of  the  right  eye 
by  a  small  fire-work  (a  so-called  "  frog")  caused  severe  pain,  which 
gradually  increased,  and  spread  over  the  corresponding  half  of 
the  head.  There  were  excessive  lachrymation  and  photophobia. 
Three  weeks  later,  Dr.  v.  Blodau  observed  a  marked  decrease  in 
the  resistance  of  the  eye,  and  a  reduction  of  its  volume.  Simul- 
taneously there  was  a  slight  adhesion  of  the  iris  with  the  capsule 
of  the  lens  in  the  outer  lower  quadrant,  but  the  iris  still  reacted 
under  the  influence  of  light.  Seven  weeks  after  the  injury,  when 
the  patient  came  under  my  treatment,  the  eye  was  still  very  soft 
and  somewhat  smaller  than  the  other,  the  cornea  unchanged,  and 
surrounded  by  a  slight  injection.  Upon  the  iris  was  the  small 
synechia  above  referred  to;  the  lens  and  the  vitreous  body  were 
absolutely  transparent.  In  the  equatorial  region  there  were  slight 
changes  in  the  choroidal  pigment,  the  retinal  veins  were  wide,  the 
retina  was  absolutely  transparent,  the  optic  nerve  unchanged. 
The  eye  and  the  upper  margin  of  the  orbit  were  very  sensitive  to 
pressure;  the  temple  and  forehead  were  likewise  sensitive,  but  in  a 
less  degree.  Vision  was  greatly  impaired,  so  that  fingers  could  be 
counted  at  a  distance  of  only  about  a  foot ;  the  field  of  vision  was 
free.  Two  years  later,  Dr.  v.  Blodau  found  the  tension  of  the 
right  eye  nearly  the  same  as  that  of  the  left,  but  it  lay  somewhat 
deeper,  and  was  sensitive  to  pressure.  Vision  had  improved  so 
much  that  the  patient,  with  the  right  eye,  with  convex  10,  could 
read  No.  II.  of  Snellen's  test  letters  at  a  distance  of  twelve  inches. 

*  Arch.  f.  Ophth.,  B.  xiii.  2,  pag.  407. 


AMBLYOPIA  AND  AMAUROSIS. 


Under  this  head  we  include  all  those  disturbances  of  vision 
Avhich  we  have  not  already  discussed,  and  which  are  caused  neither 
by  anomalies  of  refraction  or  of  accommodation,  nor  by  visible 
changes  in  the  refracting  media  or  in  the  inner  tunics  of  the  eyes. 

The  test  of  vision  in  amblyopia  demands  therefore,  in  the  first 
place,  the  determination  of  the  condition  of  refraction,  the  range 
of  accommodation,  and  the  distinctness  of  vision.  An  exact  de- 
termination of  the  condition  of  refraction  by  the  usual  method  is 
difficult  by  reason  of  the  indistinctness  of  vision,  and  accordingly 
the  examination  by  means  of  the  ophthalmoscope  is  in  these  cases 
a  great  help  in  diagnosis. 

That  accommodation  also  suffers  in  many  cases  of  amblyopia 
is  shown  by  the  fact  that  for  short  distances,  for  instance,  when 
reading,  better  vision  is  frequently  obtained  through  convex  lenses 
of  6  to  12  inches  focal  distance.  This  cannot  be  accounted  for 
by  the  enlargement  of  the  images.  Where  vision  is  diminished, 
an  exact  determination  of  the  near  point  is  of  course  still  more 
difiicult  than  the  diagnosis  of  the  condition  of  refraction. 

In  testing  vision,  it  is  well  to  employ  as  many  different  methods 
as  possible.  If  we  wish  to  determine  the  degree  of  usefulness  of 
an  eye,  it  is  not  sufficient  simply  to  ascertain  the  smallest  visual 
angle  under  which  single  letters  can  be  recognized,  but  it  is  quite 
as  important  to  test  the  facility  with  which  print  of  different 
sizes  can  be  read. 

Furthermore,  the  examination  of  the  field  of  vision  is  of  great 
importance.  The  simplest  method  by  wdiich  to  determine  at  the 
same  time  both  the  limitation  of  the  visual  field  and  the  distinct- 
ness of  indirect  vision  is  that  given  by  Donders,*  the  principle  of 
which  is  that  the  observer  institutes  at  the  same  time  a  parallel 
experiment  with  his  own  eyes.     The  observer  places  his  eye  in 


*  Arch.  f.  Ophth.,  B.  iii.  1,  pag.  147. 
526 


EXAMINATION   OF   THE  VISUAL    FIELD.  527 

the  same  horizontal  plane  with  that  of  the  patient's  eye,  and  while 
the  left  eye  of  the  patient  is  directed  upon  the  right  eye  of  the 
observer,  or  ince  versa,  the  other  eye  of  both  being  closed,  the 
hand  or  some  other  suitable  object  is  moved  in  the  middle,  between 
the  examiner's  and  the  examined  eye.  In  this  way  not  only  the 
limits  but  also  the  distinctness  of  indirect  vision  are  easily  deter- 
mined. Moreover,  the  examiner  has  the  advantage  of  being  able 
to  observe  that  the  examined  eye  maintains  continually  the  proper 
fixation,  an  important  point,  as  the  inclination  of  the  patient 
always  is  to  direct  the  axis  of  vision  upon  the  object.  In  order 
to  test  the  extreme  limits  of  the  visual  field,  the  test  object  of 
course  must  be  removed  farther  from  the  observer,  and  the 
parallel  test  then  ceases. 

In  order  to  sketch  the  limits  of  the  visual  field,  a  perpendic- 
ular table  is  employed,  upon  which  a  large  paper  of  a  dark-blue 
color  is  fastened;  a  distinct  fixation  object  is  placed  at  the  middle. 
One  eye  is  now  closed,  and  the  other  is  placed  opposite  the  fix- 
ation object,  which  may  be  a  piece  of  chalk  or  a  small  white  ball 
fastened  upon  a  long,  thin,  dark  rod,  and  which  is  then  moved 
from  the  centre  of  the  visual  field  toward  the  periphery.  The 
points  upon  the  perij)hery  of  the  visual  field,  at  which  slight 
movements  of  the  object  can  still  be  seen,  are  now  marked  upon 
the  paper.  When  in  this  manner  numerous  boundary-points  of 
indirect  vision  are  determined,  we  have  by  uniting  them  the  bound- 
ary-line of  the  field  of  vision.  If  the  test  object  be  moved  in 
the  opposite  direction,  that  is,  from  the  periphery  toward  the 
centre,  the  limits  of  the  visual  field  are  often  somewhat  smaller. 
Instead  of  copying  the  sketch  upon  a  smaller  scale,  it  is  better  to 
preserve  it  as  it  is.  Of  course,  not  only  must  the  distance  between 
the  eye  and  the  paper  remain  unchanged  during  the  examination, 
but  also,  in  order  to  get  sketches  which  can  be  compared  with  each 
other,  different  examinations  must  always  be  made  at  one  and  the 
same  distance.  The  simplest  way  to  do  this  is  to  direct  the  patient 
to  hold  a  rod,  some  30  cm.  long,  by  pressing  one  end  of  it  with 
his  forehead,  while  its  other  end  rests  against  the  paper. 

This  method  is  quite  sufficient  for  defects  in  the  neighborhood 
of  the  fixation-point,  but  is  not  suitable  for  determining  the  func- 
tional activity  of  the  retina  at  its  periphery.  For  instance,  if 
the  board  upon  which  we  wish  to  sketch  the  visual  field  be  at 


528  AMBLYOPIA   CONGENITA. 

a  distance  of  30  cm.  from  the  eye,  a  retinal  point  45°  from  the 
macula  lutea  would  be  projected  upon  the  board  at  a  distance 
of  about  30  cm.  from  the  fixation-point,  and  in  order  to  sketch 
the  visual  field  corresponding  to  a  breadth  of  75°  of  the  retina, 
the  board  must  measure  more  than  two  metres  in  every  diameter. 
These  difficulties  are  overcome  by  projecting  the  visual  field 
upon  the  inner  surface  of  a  hemisphere,  as  Forster*  first  suggested. ' 
An  instrument  constructed  on  this  principle,  and  called  a  perim- 
eter, is  indispensable  for  examining  the  perij)hery  of  the  visual  field. 

From  what  has  been  said,  it  appears  that  tlie  definition  of 
amblyopia  is,  for  the  most  part,  a  negative  one.  From  this  it 
follows  that  it  is  impossible  to  classify  its  various  forms  upou 
any  anatomical  principles,  and  even  clinically  only  certain  indis- 
tinctly defined  forms  can  be  described. 

In  the  first  ])lace,  there  is  one  form  which  is  called  amblyopia 
congenita.  Its  characteristic  is  that,  without  any  external  or  oph- 
thalmoscopic anomalies,  and  witii  a  full  visual  field,  there  is  a  con- 
genital, permanent,  and  more  or  less  considerable  imperfection  of 
vision.  Those  forms  of  congenital  amblyopia  or  amaurosis  Avhich 
are  connected  with  an  abnormal  smallness  of  the  eye,  or  which 
depend  upon  pigmentation  of  the  retina,  or  cases  where  these 
anomalies  appear  during  the  first  year  of  life,  do  not  belong  in 
this  class. 

This  form  of  amblyopia  may  occur  in  both  eyes  simultaneously, 
or  in  one  eye  alone.  Slight  degrees  of  it,  with  vision  of,  say  from 
J  to  ^,  occur  as  a  binocular  condition  in  high  grades  of  hyperme- 
tropia,  and  w^ith  meridional  asymmetry,  less  frequently  with  em- 
metro[)ia  or  myopia.  The  highest  degrees  do  not  appear  to  occur 
in  both  eyes  at  once.  With  a  free  visual  field  and  an  absolutely 
normal  fundus,  fingers  can  still  be  counted  only  at  a  distance  of  a 
few  feet,  and  this  condition  may  last  life-long.  Frequently,  too, 
fixation  is  uncertain  and  eccentric, — that  is,  a  retinal  point  is  used 
lying  to  one  side  of  the  fovea  centralis.  Strabismus  exists  in  many 
of  these  cases,  and  for  this  reason  the  amblyopia  has  been  regarded 
as  the  consequence  of  the  squint,  and  has  therefore  been  called 
amblyopia  ex  anopsia. 

*  Klin.  Monatsbl.,  18G9,  pag.  412. 


COLOR-BLINDNESS.  529 

The  arguments  against  this  view  have  been  already  given  (see 
pages  161  to  163).  A  high  degree  of  this  form  of  amblyopia  also 
occurs  in  one  eye,  and,  since  it  has  been  observed  in  eyes  which 
have  corneal  opacities,  it  has  been  thought  that  the  amblyopia  in 
these  cases,  just  as  in  those  with  strabismus,  depended  upon  non- 
use.  The  proof,  however,  that  the  amblyopia  was  caused  by  the 
corneal  opacities  has  never  been  offered.  This,  of  course,  is  inde- 
pendent of  tiie  indistinctness  of  the  retinal  images  caused  by  the 
opacities.  The  simple  occurrence  of  this  form  of  amblyopia  in 
eyes  having  at  the  same  time  corneal  opacities  proves  nothing, 
since  there  is  no  reason  why  eyes  affected  with  amblyopia  congenita 
should  not  be  attacked  by  keratitis. 

In  concluding  the  subject  of  amblyopia  congenita,  color-blind- 
ness should  be  mentioned.  Vision  may  be  quite  normal,  but  the 
capacity  to  distinguish  colors  is  either  entirely  wanting  or  very 
imperfect.  If,  as  according  to  the  hypothesis  of  Thomas  Young,* 
the  perception  of  colors  depends  upon  the  three  fundamental  per- 
ceptions of  red,  green,  and  violet,  then  there  w^ould  be  color-blind- 
ness whenever  any  one  of  these  fundamental  perceptions  is  want- 
ing. All  colors  M'hicli  the  color-blind  patient  recognizes  may  be 
formed  by  the  union  of  two  fundamental  colors.  The  perception 
of  red  seems  to  be  the  one  that  is  oftenest  wanting.  Iled-blindness 
(anerythropsia,  according  to  Goethe)  is,  therefore,  the  commonest 
form  of  color-blindness;  but  it  appears  that  eitlier  of  the  other  two 
fundamental  perceptions  may  be  wanting. 

Acquired  color-blindness,  without  considerable  diminution  of 
vision,  is  a  very  rare  occurrence,  while  as  a  symptom  of  ambly- 
opic disease  it  is  quite  frequent. 

Among  the  disturbances  of  vision  which  occur  without  any 
percej)tible  ophthalmoscopic  changes  is  that  form  of  hemeralopia 
which  appears  as  an  acute  pathological  process. 

The  essential  symptoms  of  the  disease  are  that  distinct  vision  is 
possible  only  by  intense  illumination,  while  slightly  illuminated 
retinal  images  cannot  be  perceived.  The  condition  is  that  of 
torpor  retinae. 

*  Helmholtz,  Physiologische  Optik,  pag.  291, 


530  HEMERALOPIA. 

By  daylight,  and  in  general  by  bright  illumination,  vision  is 
quite  good.  Only  exceptionally,  and  in  old  cases,  is  there  also  a 
partial  loss  of  central  vision.  Examined  by  bright  daylight,  the 
visual  field  is  generally  free;  still,  in  extreme  cases,  even  by  bright 
daylight,  there  may  be  peripheral  defects.  Upon  diminishing  the 
intensity  of  the  illumination  there  occurs  a  disproportionate  weak- 
ening both  of  central  and  of  eccentric  vision,  so  that,  in  general 
terms,  the  visual  field  becomes  more  contracted  the  weaker  the 
illumination. 

Forster*  found,  in  most  of  his  cases,  the  torpor  retinfe  greatest 
in  the  region  of  the  macula  lutea, — that  is,  eccentric  vision  was 
better  than  central.  The  reverse  seems  oftener  to  be  the  case,  so 
tjjat  as  the  illumination  diminishes  the  macula  lutea  longest 
retains  its  sensitiveness,  while  the  visual  field  contracts  from  the 
periphery  inward. 

So  soon  as  the  illumination  becomes  so  weak  that  the  sensitive- 
ness of  the  retina  is  considerably  diminished,  the  pupils  generally 
dilate  strongly. 

Forster,  moreover,  observed  a  simultaneous  decrease  of  the 
ability  to  recognize  colors.  With  an  illumination  which,  for 
healthy  eyes,  was  quite  sufficient  for  the  recognition  of  colors, 
carmine-red  and  indigo-blue  were  mistaken  for  black.  Yellow 
and  green  were  best  recognized,  but  the  first  was  sometimes 
mistaken  for  white. 

Alfred  Graefef  observed  a  difficulty  in  the  movement  of  con- 
vergence and  a  decrease  of  the  ability  to  overcome  prisms, — that 
is,  to  unite  double  images  by  the  action  of  certain  muscles.  More- 
over, in  most  of  the  cases  observed  by  him,  with  decreased  illumi- 
nation a  limitation  of  the  range  of  accommodation  appeared  to 
exist  before  the  torpor  retinae  became  very  decided. 

Hemeralopia  is  not,  as  was  formerly  supposed,  dependent  upon 
the  time  of  day.  Its  apparent  periodicity  is  owing  simply  to  the 
fact  that  the  darkness  of  night  comes  on  regularly,  and  all  its  symp- 
toms may  be  caused  at  any  time  of  day  by  any  arrangement  which 
diminishes  the  illumination.  If  the  patient  be  led  from  the  bright 
daylight,  he  sees  at  first  very  poorly,  and  it  is  only  after  some  time 

*  Ueber  Hemeralopie,  Breslau,  1857. 
t  Arch.  f.  Ophth.,  B.  v.  1,  pag.  112. 


HEMERALOPIA.  531 

that  he  begins  gradually  to  recognize  objects.  The  same  is  the 
case  with  normal  eyes,  except  that  with  hemeralopia  the  indistinct- 
ness of  vision  is  at  first  much  greater,  more  time  is  needed  to  adapt 
the  retina  to  the  diminished  intensity  of  light,  and,  at  best,  vision 
remains  far  below  that  of  normal  eyes. 

Both  eyes  are  always  affected,  but  not  always  in  the  same  degree. 

The  changes  in  the  conjunctiva,  which  some  authors  have  ob- 
served simultaneously  with  hemeralopia, — for  instance,  dryness, 
with  fatty  degeneration  of  its  epithelium,  or  the  appearance  of 
bright  spots  upon  it, — have  probably  nothing  to  do  with  the 
hemeralopia,  but  are  to  be  regarded  only  as  accidental  complica- 
tions, or  as  the  co-effects  of  the  same  causes. 

The  causes  of  hemeralopia  have  been  by  no  means  fully  ex- 
plained, but  this  much  may  be  said  with  certainty,  that  insuffi- 
cient nutrition  and  the  influence  of  dazzling  light  are  the  principal 
factors.  Where  the  disease  occurs  as  an  epidemic,  it  generally 
seems  to  be  due  to  the  simultaneous  influence  of  these  causes 
upon  a  great  number  of  individuals,  for  instance,  among  troops, 
sailors,  prisoners,  etc.  Especially  upon  shipboard  a  connection 
has  been  observed  between  it  and  scorbutus.  The  disease  occurs 
mostly  in  the  tropics,  where  the  sunshine  is  most  dazzling.  It 
is  often  described  by  sailors  as  "moon-blindness."  The  influence 
of  insufficient  nutrition  is  shown  by  the  fact  that  the  disease 
scarcely  ever  occurs  in  well-nourished  persons ;  for  instance,  on 
shipboard  the  officers,  who  are  better  fed,  are  exempt  from  it, 
although  they  equally  with  the  crew  are  exposed  to  the  dazzling 
light.  In  some  of  the  cases  observed  by  Forster  the  dazzling  by 
light  could  scarcely  be  regarded  as  the  cause,  while  it  probably 
was  in  certain  other  cases  in  which  he  found  the  greatest  torpor 
in  the  region  of  the  macula  lutea.  The  so-called  snow-blindness 
appears  to  be  due  to  similar  causes. 

The  treatment  consists  principally  in  suitable  nutrition  and  in 
protection  against  dazzling  light.  Cod-liver  oil,  as  recommended 
by  Despont,*  appears  to  act  simply  as  nutritious  food.  Fdrster 
recommended  that  the  patients  be  kept  for  some  time  in  an  abso- 
lutely dark  room.  Where  this  is  not  practicable,  dark-blue  pro- 
tective spectacles  should  be  worn. 

*  Traitement  de  I'Heineralopic,  etc.,  Paris,  1863. 


532  ANESTHESIA   OF   THE   EETINA. 

A  form  of  amblyopia  well  characterized  by  its  clinical  pecu- 
liarities consists  in  a  diminished  sensibility  of  the  retina,  usually 
described  as  "  anresthesia  of  the  retina."  In  i)iost  of  these  cases 
a  greater  or  less  loss  of  acuity  of  vision  is  generally  associated 
with  an  intolerance  of  light. 

This  affection  is  often  connected  with  other  nervous  diseases, — 
with  hysteria,  anaesthesia,  or  hypersesthesia  of  the  sensitive  cu- 
taneous nerves,  or  with  spasmodic  aifections,  frequently,  too,  with 
paralyses  of  certain  motor  nerves.  It  occurs  also  in  perfectly 
healthy  persons.  It  is  relatively  most  frequent  in  women  and 
children.  In  many  cases,  especially  where  the  disease  is  unilateral, 
wounds,  contusions  of  the  eye,  etc.,  or  reflex  irritations  proceeding 
from  carious  teeth,  are  stated  as  causes.  That  reflex  action  really 
plays  an  important  part  is  proved  by  the  fact  that  diminution  of 
central  vision,  with  concentric  contraction  of  the  visual  field  and 
without  any  ophthalmoscopic  changes,  occurs  as  a  sympathetic 
affection,  and  disappears  in  the  course  of  some  weeks  after  the 
epucleation  of  the  other  eye,  which  of  course  is  already  blinded 
by  irido-cyclitis  or  irido-choroiditis. 

The  essential  characteristics  of  this  form  of  disease  are  the 
following : 

Central  vision  is  generally  only  moderately  diminished;  it  is 
seldom  less  than  ^  or  J  normal;  still,  exceptionally,  there  may 
be  a  very  considerable  loss  of  central  vision. 

There  is  always  a  great  contraction  of  the  visual  field,  generally 
concentric,  but  often  with  very  striking  variations  in  its  form. 
The  visual  field  often  shows  great  variations  in  its  extent  when 
examined  according  to  different  methods.  In  general,  however, 
the  statements  of  the  patients,  especially  in  the  hysterical  form  of 
the  affection,  are  decidedly  irrational  and  uncertain. 

Simultaneously  there  is  often  hypersesthesia  of  the  retina,  which 
manifests  itself  by  a  moderate  sensation  of  dazzling,  or  it  may  be 
very  marked,  especially  with  hysteria.  By  a  moderated  light,  or 
by  means  of  colored  (dark-blue)  glasses,  vision  is  not  diminished 
as  it  normally  would  be ;  it  may  even  be  improved ;  so,  too,  with 
reference  to  the  limitation  of  the  visual  field.  Such  patients 
frequently  affirm  that  they  see  better  through  any  ordinary  piece 
of  glass,  or  through  a  weak  prism,  than  with  the  naked  eye. 

The  disease  almost  always  occurs  on  both  sides,  although  it 


ANESTHESIA   OF   THE   EETIXA.  533 

may  be  of  different  degrees ;  exceptionally,  it  occurs  only  on  one 
side. 

The  oj3tic  nerve  remains  normal  even  when  the  disease  lasts  a 
long  time. 

The  disturbances  of  vision  often  appear  in  the  course  of  a  few- 
days.  In  other  cases,  on  the  contrary,  the  amblyopia  and  the 
contraction  of  the  visual  field  come  on  very  gradually,  being 
preceded  for  weeks  by  asthenopia,  vision  being  still  good,  or  but 
slightly  diminished.  The  contraction  of  the  visual  field  and  the 
diminution  of  vision,  moreover,  do  not  always  stand  in  correspond- 
ing relation.  I  have  repeatedly  observed  the  central  vision  very 
nearly  restored  while  there  was  still  a  very  considerable  contrac- 
tion of  the  visual  field. 

The  prognosis  is  generally  favorable.  Recovery  often  occurs 
in  the  course  of  a  few  weeks,  but  in  other  cases  it  is  months — even 
more  than  a  year — before  vision  and  the  visual  field  become  again 
normal.  Peripheral  contraction  of  the  visual  field  and  hyperties- 
thesia  seldom  remain.  Amaurotic  blindness  does  not  appear  to  be 
caused. 

Von  Graefe  recommended  that  the  patient  be  kept  in  a  dark- 
ened room,  in  which  the  light  should  be  gradually  increased  after 
about  the  sixth  day.  Later,  it  is  sufficient  to  protect  the  eyes  from 
the  light  by  dark-blue  or  gray  spectacles.  Von  Graefe  recom- 
mended for  internal  administration  principally  the  preparations  of 
zinc,  in  increasing  doses  (zinc.  lact.  0.1  to  0.3  daily  =  gr.  jss.  to 
gr.  ivss.). 

Of  course,  during  treatment  all  straining  of  the  eyes  must  be 
sedulously  avoided. 

The  designation  of  this  form  of  amblyopia  as  anaesthesia  retinae 
is  not  very  appropriate.  This  name  would  be  equally  suitable  for 
many  other  forms  of  amblyopia.  The  choice  of  this  name  was 
founded  upon  the  idea  that  tlie  condition  consisted  essentially  in 
an  interruption  of  nervous  communication  between  the  layer  of  the 
rods  and  cones  and  that  of  the  nerve  fibres  in  the  retina;  at  least 
Von  Graefe*  drew^  this  conclusion  from  the  fact  that  the  patients 
stated  that  the  well-known  fire  circles  could  be  produced  in  the 
eye  by  pressure  upon  that  part  of  the  retina  corresponding  to  the 

*  Klin.  Monatsbl.,  1865,  pag.  263. 


534  HYPER^ESTIIESIA    OF   THE   RETINA. 

defect  in  the  visual  field.  Now,  one  can  by  no  means  always  be 
certain  that  external  pressure  on  the  eye  always  is  exactly  upon 
that  point  in  the  retina  corresponding  to  a  defect  in  the  visual 
field,  and  not  upon  some  neighboring  point.  I  have  not  been  able 
in  all  cases  to  produce  tlie  phenomenon ;  the  fire  circles  often  abso- 
lutely fail.  Moreover,  how  do  we  know  that  the  fire  circles  de- 
pend upon  an  excitation  of  tlie  nerve  fibres  ?  The  circumstance 
that  the  centres  of  the  fire  circles  correspond  Avith  the  points  of 
pressure  makes  it  probable  that^the  phenomenon  is  due  to  an  ex- 
citation of  the  rods  and  cones.  If  it  depended  upon  an  irritation 
of  the  layer  of  nerve  fibres,  the  appearances  would  not  assume  the 
form  of  fire  circles,  but  would  be  flame-shaped,  streaming  toward 
the  periphery,  corresponding  to  the  anatomical  arrangement  of 
the  terminal  apparatus  of  the  nerve  fibres  pressed  upon. 

Considering  the  im})ortant  role  which  the  contraction  of  the 
visual  field  plays  in  this  disease,  the  most  expressive  name  for  it 
would  be  "  visual-field  amblyopia." 

It  may  here  be  mentioned  that  this  is  the  only  form  of  ambly- 
opia which  prevails  most  in  women  and  children.  All  other  forms 
are  more  frequent  in  men  than  in  women,  which  may  be  explained 
by  the  nature  of  the  exciting  causes  of  the  disease. 

A  pure  hyperesthesia  of  the  retina — that  is,  without  diminution 
of  central  or  peripheral  vision — also  occurs,  and  may  continue  a 
long  time  without  ever  causing  amblyopia,  or  contraction  of  the 
visual  field.  Often  there  is  a  great  susceptibility  to  after-images, 
and  long  continuance  of  the  same,  as  well  as  subjective  light  and 
color  symptoms. 

Quite  a  large  group  of  amblyopire  are  characterized  by  a  dimi- 
nution of  vision  without  limitation  of  the  visual  field,  and  with- 
out a  trace  of  central  scotoma.  The  perception  of  color  is  gener- 
ally unchanged;  still,  color-blindness  does  simultaneously  occur. 
The  fundus  appears  perfectly  normal,  aside  from  a  hyperemia  of 
the  retina  which  is  often  present,  but  even  then  not  very  marked. 
Even  after  the  amblyopia  has  existed  a  long  time,  the  optic  nerve 
may  remain  normal  or  it  may  atrophy.  Both  eyes  are  always 
aifected  at  the  same  time,  and  generally  to  an  equal  degree. 

The  causes  generally  appear  to  lie  in  the  dietetic  relations  and 
mode  of  life  of  the  patient.  The  following  causes  have  been  ob- 
served :  constipation,  irregularity  of  the  circulation,  with  coldness 


SCOTOMA    CENTEALE.  535 

of  the  extremities,  especially  of  the  feet,  the  suppression  of  habit- 
ual hemorrhages,  or  of  pathological  or  physiological  secretions, 
irregular  sleep,  undue  straining  of  the  eyes,  excess  in  venery,  im- 
moderate smoking,  but  above  all,  the  abuse  of  spirituous  liquors. 
All  these  causes  are  operative  alone,  but  several  are  more  fre- 
quently combined.  The  effect  of  the  abuse  of  alcoholic"  drink 
may  explain  the  fact  that  this  form  of  amblyopia  is  much  more 
frequent  in  men  than  in  women.  The  so-called  "  amblyopia  pota- 
toria,"  which  is  simple  amblyopia  not  affecting  the  extent  of  the 
visual  field,  and  without  central  scotoma,  may  be  regarded  as  the 
representative  of  the  entire  group.  Indeed,  central  scotoma  is  not 
infrequently  due  to  the  abuse  of  alcoholic  stimulants. 

The  prognosis  depends  principally  upon  whether  it  is  possible 
or  not  to  remove  the  exciting  cause,  as,  for  instance,  the  use  of 
alcohol.  If  the  optic  nerve  has  already  become  pale,  no  great 
improvement  can  be  expected. 

The  first  object  of  the  treatment  must,  of  course,  be  to  remove 
the  exciting  cause;  next,  there  should  be  a  derivative  treatment 
proportionate  to  the  condition  of  the  strength.  Generally,  in 
persons  otherwise  healthy,  blood  is  drawn  from  the  temple,  and 
afterwards  diaphoretics  and  cathartics  are  employed. 

To  complete  this  subject,  mention  should  be  made  of  amblyopia 
caused  by  lead  poisoning,  which  likewise  attacks  both  eyes  at  the 
same  time.  The  amblyopia  may  develop  rapidly,  and  in  a  few 
days  lead  to  almost  complete  loss  of  the  perception  of  light.  The 
pupils  are  at  the  same  time  generally  dilated.  The  prognosis 
appears  to  be  generally  favorable,  since  the  blindness  may  pass 
away  as  rapidly  as  it  has  come  on.  Color-blindness  may  remain.* 
In  the  treatment  the  use  of  opiates  is  specially  indicated,  as  indeed 
is  the  case  in  all  lead  poisoning. 

Under  the  name  "scotoma  centrale"  are  included  all  those  forms 
of  amblyopia  in  which  a  diminution  of  central  vision  is  more  or 
less  sharply  defined  in  a  free  visual  field.  This  symptom  is  so 
characteristic  as  to  form  the  most  prominent  feature  of  the  disease. 
But  it  should  be  remarked  that  various  pathological  processes 
may  cause  this  same  symptom.     It  may  be  positively  asserted, 

*  Dr.  Haase,  Klin.  Monatsbl.,  1867,  pag.  225. 


536  SCOTOMA   CENTRALE. 

for  instance,  that  there  are  forms  of  nenritis  or  neuro-retinitis 
which  may  cause  scotoma  centrale,  but  from  that  it  does  not  follow 
that  this  symptom  is  always  caused  by  neuritis.  Central  vision 
may  become  so  poor  that  the  patients  prefer  to  use,  instead  of  the 
macula  lutea,  some  retinal  point  lying  near  it,  so  that  eccentric 
fixation  occurs.  Indeed,  it  may  happen  that  a  flame  in  the  direc- 
tion of  the  line  of  vision  cannot  be  seen  ;  it  disappears  so  soon  as 
its  image  reflected  on  the  cornea  corresponds  with  the  centre  of 
the  pupil.  Generally,  however,  the  vision  of  the  macula  lutea  is 
nearly  the  same  as  that  of  the  neighboring  retinal  zone,  or  it  may 
remain  somewhat  better  than  that. 

The  existence  of  central  scotoma  is  often  demonstrated  while 
practising  one  of  the  above  methods  for  testing  the  visual  field 
by  daylight,  or  more  easily  in  other  cases  by  dim  lamplight. 
Nevertheless  there  are  frequently  cases  in  which  these  methods  do 
not  prove  sufficient,  and  in  which,  as  Leber*  has  shown,  the  test 
of  the  perception  of  colors  is  a  very  convenient  and  sure  method 
by  which  to  recognize  the  nature  of  the  lesion.  One  proceeds  ex- 
actly in  the  manner  above  described,  except  that  small  })ieces  of 
colored  paper  are  used  instead  of  a  piece  of  chalk  or  a  white  ball, 
and  the  boundary  is  noted  at  which  the  patient  begins  to  lose  the 
proper  perception  of  color. 

There  is  always  an  abnormal  perception  of  color  within  the 
reo;:lon  of  the  central  scotoma. 

■  The  affection  is  generally  bilateral.  It  is  seldom  that  it  occurs 
only  in  one  eye.  Frequently,  however,  the  degree  of  amblyopia 
in  the  two  eyes  differs.  The  form  of  the  scotoma  generally  cor- 
responds in  the  two  eyes.  Its  greatest  diameter  may  lie  either  in 
the  vertical  or  in  the  horizontal  direction.  Forster'sf  investiga- 
tions have  shown  that  in  most  cases  the  scotoma  extends  to 
^lariotte's  blind  spot,  so  that  the  part  of  the  retina  in  which 
perception  is  diminished  includes  the  oj)tic  disc. 

Central  scotoma  appears  either  suddenly  or  it  develops  in  the 
course  of  a  few  weeks  in  one  eye  after  the  other,  or  simultaneously 
in  both,  by  the  enlargement  of  a  defect  which  at  first  does  not 
always  correspond  with  the  fixation-point.     The  degree  of  am- 


*  Arch.  f.  Ophth.,  B.  xv.  3,  pag.  26. 
f  Annales  d'Oculistique,  18G8,  pag.  11. 


SCOTOMA    CENTRALE.  537 

blyopia  is  varied ;  generally  the  large  letters  of  the  test  type  are 
still  recognized. 

Freqnently  there  are  at  first  no  ophthalmoscopic  changes  either 
in  the  optic  nerve  or  in  the  macula  lutea;  in  other  cases  there  ap- 
pears to  be  an  opacity  of  the  retina,  not,  however,  in  the  region 
of  the  macula  lutea,  as  one  would  suppose,  but  in  the  periphery 
of  the  optic  disc.  Slight,  mostly  striated,  white  opacities  are  situ- 
ated, some  upon  the  surface  of  the  optic  disc  and  some  radiating 
a  distance  into  the  retina ;  they  cover  the  place  of  exit  of  the 
vessels,  and  frequently  extend  farther  into  the  retina  along  the 
course  of  the  vessels. 

Hypersemia  of  the  retina  and  of  the  optic  nerve,  and  small 
ecchymoses  close  to  the  nerve,  also  occur.  In  the  later  stages, 
but  quite  early,  too,  in  many  cases,  there  occurs  a  whitish  or 
bluish  discoloration  of  the  optic  disc,  which,  however,  is  almost 
invariably  confined  to  its  temporal  half,  while  the  color  of  the 
other  half  remains  normal  or  nearly  so. 

On  these  grounds  Von  Graefe*  regarded  central  scotoma  as 
caused  by  a  disease  of  the  optic  nerve,  and  Leber  regards  the 
changes  caused  by  a  retro-ocular  neuritis  as  the  essential  element 
of  the  disease. 

Concerning  the  causes  nothing  is  certainly  known.  The  cir- 
cumstance that  this  form  of  amblyopia  as  well  as  most  others 
occurs  almost  exclusively  in  men  and  only  exceptionally  in  women, 
may  give  some  clue  to  its  etiology.  The  abuse  of  alcohol  and 
tobacco,  repeated  wetting,  and  colds,  appear  to  exercise  an  influ- 
ence upon  it.     The  disease  also  appears  to  be  hereditary. 

The  prognosis  is  essentially  influenced  by  the  behavior  of  the 
peripheral  visual  field.  So  long  as  eccentric  vision  remains 
normal,  eventual  blindness  is  not  to  be  feared.  But  if,  on  the 
contrary,  eccentric  vision  fail,  if  the  field  of  vision  contract  at 
its  periphery,  or  if  sector-shaped  defects  radiating  from  the  sco- 
toma appear  in  it,  blindness  from  atrophy  of  the  optic  nerve  may 
be  regarded  as  coming  on. 

In  recent  cases  a  derivative  treatment  is  to  be  pursued, — bleed- 
ing, foot-baths,  diaphoretics,  cathartics,  etc.  In  many  cases  the 
iodide  of  potassium  does  good  service. 


*  Klin.  Monatsbl.,  1865,  pag.  209. 
35 


638  PEOGEESSIVE   ATEOPHY   OF   THE   OPTIC   NERVE. 

If  the  optic  nerve  have  ah^eady  become  pale,  no  great  improve- 
ment can  be  expected. 

Progressive  atrophy  of  the  optic  nerve  generally  first  manifests 
itself  by  contraction  of  the  visual  field,  which  occurs  either  in 
both  eyes  at  once  or,  more  generally,  first  in  one  eye  and  then  in 
the  other.  In  either  case,  even  when  there  is  a  very  long  interval, 
of  perhaps  several  years,  between  the  appearance  of  the  disease  in 
the  two  eyes,  it  generally  aifects  them  both  symmetrically,  so  that 
the  beginning  of  the  disease  is  observed  in  both  eyes  in  a  corre- 
sjionding  part  of  the  visual  field,  be  it  on  its  median  or  its  tem- 
poral periphery. 

The  upper  temporal  part  of  the  visual  field  •  ajjpears  oftenest 
to  be  the  first  affected ;  the  contraction  begins  less  frequently  in 
the  median  periphery.  The  defect  in  the  visual  field  in  these  cases 
appears  never  to  be  sharply  defined,  but  is  divided  from  the  part 
whose  function  is  still  normal  by  a  zone  in  which  vision  is  more 
or  less  diminished.  Central  vision,  too,  begins  early  to  fail;  the 
normal  perception  of  color  is  at  the  same  time  often  interfered  with. 

If  the  defect  in  the  visual  field  have  already  attained  a  certain 
dimension,  eccentric  vision  in  the  entire  periphery  is  generally  di- 
minished. The  defect  gradually  approaches  the  fixation-point,  so 
that  frequently  at  a  certain  period  of  the  disease  eccentric  vision 
is  better  than  central,  and  absolute  blindness  generally  follows. 

The  optic  nerve  always  presents  the  appearances  of  atrophic 
degeneration,  described  on  page  491,  which  appearances  may 
either  precede  or  follow  the  disturbances  of  vision.  Of  course 
the  opportunity  of  making  such  observations  is  most  frequent  in 
the  eye  which  is  attacked  last. 

The  course  of  the  disease  varies  as  to  the  time  which  ensues 
before  absolute  blindness  of  the  eye  affected,  which  varies  from 
some  mouths  to  some  years,  and  further,  in  reference  to  the  time 
when  the  affection  appears  in  the  second  eye,  which  may  be  very 
soon  after  the  beginning  of  the  disease  in  the  first  eye,  or  even 
years  later. 

In  a  great  number  of  these  cases  the  pathological  process  is 
limited  to  the  fibres  of  the  optic  nerve  without  there  being  any 
more  central  disease.  In  many  cases  blindness  occurs  as  the  pre- 
cursor of  mental  diseases.     Quite  frequently  the  disease  of  tlie 


HEMIOPIC   DEFECTS   OF   VISUAL   FIELD.  539 

optic  nerve  is  connected  with  spinal  disease,  which,  before  vision 
was  aflFected,  manifested  itself  by  other  symptoms,  such  as  loss  of 
sensation,  uncertainty  of  the  gait,  contraction  of  the  pupil,  etc. 
According  to  Virchow,*  it  is  especially  with  the  spotted  atrophy 
of  the  spinal  cord  that  the  spotted-gray  atrophy  of  the  optic  nerve 
is  connected,  and  accordingly  the  anatomical  causes  of  the  dis- 
turbances of  vision  are  to  be  looked  for  in  the  optic  nerve  itself 
rather  than  in  the  central  organ. 

The  prognosis  is  always  very  unfavorable;  the  treatment  is 
limited  to  tonics.     Energetic  derivative  remedies  always  do  harm. 

The  hemiopic  defects  of  the  visual  field  deserve  special  men- 
tion. Hemiopia,  in  the  exact  sense  of  the  word,  includes  those 
cases  in  which  the  visual  field  is  contracted  upon  the  same  side 
in  both  eyes  ;  that  is,  the  defect  is  in  the  right  half  or  left  half 
in  both  eyes.  The  defect  may  involve  the  entire  half  of  the 
visual  field,  or  only  a  corresponding  fractional  part  of  it  on  both 
sides. 

This  homonymous  hemiopia  is  always  to  be  referred  to  some 
interruption  in  the  optic  tract  before  its  entrance  into  the  chiasm. 
Numerous  physiological  and  pathological  factsf  show  that  a  cross- 
ing (semidecussation)  of  both  optic  tracts  occurs  in  the  chiasm  in 
such  a  manner  that  the  right  optic  tract  supplies  the  temporal 
portion  of  the  right  retina  and  the  median  portion  of  the  left 
retina.  An  interruption  in  its  course  would  accordingly  blot  out 
both  left  halves  of  the  visual  field.  Generally,  but  not  always, 
these  hemiopic  defects  are  separated  from  the  normal  visual  field 
by  a  sharply  defined  line,  which  may  either  pass  through  the 
fixation-point  or  remain  at  some  distance  from  it. 

Cerebral  hemorrhage  is  the  most  frequent  cause  of  this  hemi- 
opia, and  of  course,  under  these  circumstances,  hemiopia  and  hemi- 
plegia exist  on  one  and  the  same  side.  Hemiopic  defects,  when 
not  due  to  apoplexy  or  encephalitis,  may  be  caused  by  transitory 
idiopathic  affections  of  the  optic  nervous  tract.  It  often  appears 
to  depend  upon  syphilis.     Tubercle  in  the  chiasm  was  found  as 

*  Arch.  f.  path.  Anat.,  B.  x.  pag.  192. 

f  The  semidecussation  of  the  optic  nerve  in  the  chiasm,  which  has  recently 
been  again  doubted,  may  be  regarded  as  demonstrated  by  Guddcn's  investi- 
gations (Arch.  f.  Ophth.,  B.  xx.  2,  pag.  249). 


540  HEMIOPIC   DEFECTS   OF   VISUAL   FIELD. 

the  cause  of  hemiopia.*  Some  cases  are  due  to  mysterious  causes 
in  the  nervous  system,  which  during  the  course  of  the  affection, 
and  after  recovery,  remain  unknown.  A  disease  in  the  substance 
of  the  brain  is  probably  the  cause  of  those  hemiopic  defects  which 
do  not  involve  the  entire  half  of  the  visual  field,  but  only  a  cor- 
responding fractional  part  of  it  on  both  sides,  while  an  affection 
of  the  optic  tract  is  more  probable  in  those  cases  in  which  the  defect 
on  both  sides  extends  to  a  vertical  line  dividing  the  visual  field. 
Especially  is  this  true  when  a  symptom  is  added  to  which  attention 
has  been  called  by  recent  physiological  investigations.f  After 
division  of  one  optic  tract  between  the  chiasm  and  the  brain  there 
occurs  a  dilatation  of  the  pupil  upon  the  opposite  side;  and,  in  fact, 
I  have  seen  many  cases  in  which  simultaneously  with  hemiopic 
defect  of  the  left  half  of  the  visual  field  the  pupil  of  the  left  eye 
was  evidently  dilated,  though  its  movement  remained  normal. 

In  homonymous  hemiopic  defects  which  are  limited  by  a  sharp 
boundary-line  the  prognosis  is  favorable  in  this  sense,  that  abso- 
lute blindness  is  not  to  be  feared  so  long  as  the  cerebral  disease 
causing  it  does  not  extend  to  the  other  hemisphere.  Moreover, 
an  absolute  disappearance  of  this  symptom  is  within  the  range 
of  possibility. 

In  cases  of  pure  hemiopia  the  ophthalmoscopic  appearance  of 
the  optic  disc  is  at  first,  or  during  a  long  time,  normal.  Only 
very  exceptionally,  as  Von  Graefe|  once  observed,  does  a  homon- 
ymous partial  atrophy  corresponding  to  the  defect  in  the  visual 
field  develop  in  the  course  of  a  few  years. 

Among  the  hemiopic  disturbances  of  vision  belongs  also  a 
symptom  which  generally  manifests  itself  by  a  sparkling  in  one 
half  of  tHe  visual  field.  Frequently  there  is  connected  with  it  a 
simultaneous  hemiopic  defect  of  the  visual  field  of  greater  or  less 
extent,  though  the  affection  appears  also  to  occur  unilaterally.  The 
sparkling  occurs  at  intervals  with  longer  or  shorter  pauses,  in 
many  persons  almost  daily,  and  lasts  each  time  from  a  quarter  to 
half  an  hour.  The  attacks  are  often  connected  with  hemicrania, 
but  may  occur  without  it. 

*  Dr.  Hjort,  Klin.  Monatsbl.  f.  Augenheilk.,  1867,  pag.  166. 
f  Knoll,  Beitriige  zur  Physiologie  der  Vierhugel,  Centralblatt  der  med. 
Wissenschaften,  1872,  No.  17. 

X  Klin.  Monatsbl.,  1865,  pag.  218. 


HEMIOPIC    DEFECTS   OF   VISUAL    FIELD.  541 

Listing*  designated  the  symptom  as  "  sichelformiges  Flimraer- 
scotoni."    Forsterf  proposed  the  name  amaurosis  partialis  fugax. 

It  should  be  mentioned,  in  concluding  the  subject  of  homon- 
ymous hemiopia,  that  in  very  rare  cases  bilateral  symmetrical 
limitations  of  the  visual  field,  above  and  below,  have  been 
observed,  for  which  an  anatomical  explanation  is  yet  wanting. 

If  these  defects  be  sharply  defined  from  the  normal  visual  field, 
and  there  be  no  great  diminution  of  central  vision,  a  prognosis 
may  be  made  similar  to  that  in  typical  hemiopia. 

Temporal  hemiopic  defect  is  the  name  given  to  those  limita- 
tions of  the  visual  field  which  involve  only  its  outer  half  on 
both  sides.  Still,  we  do  not  reckon  as  such,  cases  where,  as  in 
progressive  atrophy  of  the  optic  nerve,  the  defect  begins  on  the 
temporal  side  and  from  there  spreads  over  the  entire  visual  field, 
but  only  those  which  involve  simply  the  temporal  half  on  both 
sides,  and  which  remain,  for  some  time  at  least,  stationary  in  this 
condition.  Von  Graefe|  remarked  that  under  these  relations  there 
are  generally  symptoms  pointing  to  the  existence  of  a  tumor  or 
some  cause  of  pressure  at  the  base  of  the  brain,  and  the  correctness 
of  this  view  has  been  confirmed  by  numerous  observations. § 

Moreover,  there  occur  cases  in  which  the  entire  course  of  the 
disease,  or  its  complete  recovery,  renders  the  existence  of  a  tumor 
exceedingly  improbable,  and  suggests  the  idea  that  simple  inflam- 
matory processes  at  the  base  of  the  brain  may  produce  the  same 
effect.  Every  such  cause  of  disease  acting  at  the  median  line 
will,  of  course,  affect  most  the  fasciculi  cruciati  lying  near  the 
median  line,  both  before  and  behind  the  chiasm,  and  accordingly 
the  inner  halves  of  the  retinae  will  suffer  most.  Such  processes 
will  not  be  strictly  limited  to  certain  fibrous  bundles,  but  only 
the  median  bundles  will  be  first  and  most  seriously  affected,  while 
the  more  lateral  fasciculi  will  be  proportionately  less  affected,  so 
that  the  defect  in  the  visual  field  is  not  sharply  defined. 

The  prognosis  in  temporal  defects  is  generally  more  unfavorable 

*  Klin.  Monatsbl.  f.  Augenheilk.,  1867,  pag.  334. 
f  Ibid.,  1869,  pag.  422. 
X  Arch.  f.  Ophth.,  B.  ii.  2,  pag.  287. 

g  Dr.  D.  E.  Miiller,  Arch.  f.  Ophth.,  B.  viii.  1,  pag.  160;  Samisch,  Klin. 
Monatsbl.,  1865,  pag.  51. 


542  AMBLYOPIA    FROM    INTRACEANIAL    CAUSES. 

than  in  homonymous  hemiopia.  In  the  last-named  disease  the 
persistent  action  of  its  cause  only  comjDletes  the  hemiopia,  but 
never  can  cause  blindness  of  one  or  both  eyes ;  but  where  there  are 
temporal  defects  there  is  the  possibility  that  the  cause  acting  at 
the  base  of  the  brain  may  extend  its  effects  constantly  upon  both 
optic  nerves  beyond  the  limits  of  the  fasciculi  cruciati  and  lead  to 
total  obliteration  of  the  visual  field.  On  the  other  hand,  the  dis- 
ease may  halt  at  any  stage,  or  may  even  entirely  disappear.  This 
depends  essentially  upon  the  nature  of  its  cause. 

Amaurosis  is  sometimes  due  to  intracranial  causes. 

The  symptomatology  of  these  cases  varies,  of  course,  according 
to  the  nature  of  the  disease  causing  them.  Both  eyes  may  be 
affected  in  a  similar  or  dissimilar  manner,  or  the  disturbance  of 
vision  may  be  unilateral.  .  In  the  latter  case  it  must  be  assnmed 
that  the  cause  lies,  if  not  in  the  orbit,  at  any  rate  in  the  nerve 
between  the  foramen  opticum  and  the  chiasm. 

The  prognosis  depends  upon  the  nature  of  the  intracranial 
process.  It  sometimes  happens,  after  the  absence  for  several 
weeks,  or  even  months,  of  all  perception  of  light,  that  some  degree 
of  vision  returns;  or  some  remnant  of  vision  may  be  retained, 
although  atrophic  degeneration  of  the  nerve  has  begun. 

The  treatment  of  these  cases  is  directed  against  the  primary 
cerebral  disease.  Among  the  remedies  indicated  are  setons  in  the 
neck,  iodide  of  potassium,  corrosive  sublimate,  cathartics,  etc. 

We  may  here  mention  a  group  of  rather  rare  cerebral  amauroses, 
in  which,  in  both  eyes,  there  occur  sudden  disturbances  of  vision 
which  in  the  course  of  a  few  hours  or  days  become  so  great  that 
there  is  often  absolute  loss  of  the  perception  of  light,  and  still 
no  ophthalmoscopic  changes  are  visible.  This  blindness  may  dis- 
appear as  quickly  as  it  came  on. 

The  best  example  of  this  group  is  the  ursemic  amaurosis.  In 
connection  with  other  ureemic  symptoms,  such  as  headache,  a  sensa- 
tion of  heat,  languor,  shortness  of  breath,  faintness,  or  convulsions, 
there  occurs  a  sudden  loss  of  vision,  which  in  the  course  of  one 
or  two  days  may  amount  to  absolute  blindness.  There  generally 
follows  an  equally  rapid  return  of  vision,  though  not  always  in  a 
uniform  manner,  so  that  during  this  period  defects  may  appear  in 


UREMIC  AMAUROSIS.  543 

the  visual  field.  As  a  rule,  ophthalmoscopic  changes  do  not  exist; 
but  sometimes  there  is  a  slight  swelling  or  inflammatory  clouding 
of  the  optic  nerve  and  the  surrounding*  retina.  Since  albumi- 
nuria exists  in  all  these  cases,  the  simultaneous  occurrence  of  ursemic 
amaurosis  and  of  retinitis  albuminurica  is  occasionally  observed. 

In  a  similar  manner,  and  perhaps  likewise  dependent  upon  urae- 
mia, sudden  blindness  occurs  after  typhoid  fever,  scarlatina,  etc.f 

Hughlings  JacksonJ  observed  in  many  cases  of  epilepsy  that 
absolute  blindness  preceded  the  loss  of  consciousness.  But  such 
cases  occur  accompanied  by  indeterminate  symptoms,  and  when 
the  general  condition  is  apparently  good. 

The  blindness  is  often  so  absolute  that  there  is  not  the  slightest 
perception  of  light,  and  still  vision  may  return  within  a  few  days. 
Or  there  may  be  only  a  partial  improvement,  or  none  at  all,  and 
then  begins  gradually  an  atrophic  degeneration  of  the  optic  nerve. 

Often  in  these  cases  the  noticeable  fact  is  observed  that,  in  spite 
of  the  absolute  loss  of  perception  of  light,  the  reaction  of  the  pupil 
under  its  influence  remains.  Von  Graefe  explained  this  by  the 
theory  that  the  interruption  in  the  central  course  of  the  optic-nerve 
fibres  occurs  at  a  point  posterior  to  that  at  which  is  received  the 
branch  of  the  oculo-motorius,  which  supplies  the  iris,  and  upon 
whose  function  its  reflex  action  depends. 

This  fact  is  important  in  reference  to  the  prognosis,  since,  when 
the  reaction  of  the  pupil  is  retained,  a  restoration  of  vision  may 
be  expected ;  but  even  where  the  reaction  is  lost,  recovery  is  not 
absolutely  excluded.  The  normal  appearance  of  the  optic  disc 
during  the  first  days  of  the  blindness  furnishes  no  ground  for  a 
favorable  prognosis,  for  the  atrophic  degeneration  does  not  begin 
for  some  weeks  or  months. 

Mention  should  be  made  of  those  cases  of  sudden  blindness 
which  occur  in  connection  with  hemorrhage  of  the  stomach  or 
bowels  and  which  are  therefore  designated  as  amaurosis  after 
hsematemesis.  Some  days  after  a  copious  hsematemesis,  or  after 
bloody  diarrhoea,  there  follows  a  rapidly  increasing  amblyopia. 

*  Dr.  Herm.  Schmidt,  Berl.  klin.  Wochenschrift,  1870,  No.  48  und  49. 
t  Ebert,  Berl.  klin.  Wochenschrift,  1868,  No.  2. 
J  Ophth.  Hosp.  Rep.,  iv.  2,  pag.  14. 


544  AMAUROSIS   AFTER    H.EMATEMESIS. 

As  a  rule,  all  perception  of  light  is  lost  after  one  or  two  days, 
though  sometimes  a  remnant  of  vision  remains.  In  a  short  time 
atrophic  degeneration  of  the  optic  nerve  begins:  still,  the  suspicion 
first  expressed  by  Von  Graefe,*  that  this  is  due  to  primary  irrita- 
tive processes  in  the  optic  nerve,  has  much  in  its  favor. 

In  one  case,  which  I  examined  on  the  eighth  day  of  blindness, 
the  boundary-line  of  both  optic  discs  was  marked  by  a  cloud- 
ing which  extended  into  the  retina  for  a  distance  equal  to  the 
diameter  of  the  disc.  In  one  eye  there  was  a  small  retinal  hemor- 
rhage close  to  the  disc.  The  large  vessels  presented  no  marked 
changes;  the  optic  disc  was  somewhat  pale.  Later,  the  usual 
aj^pearances  of  atrophic  degeneration  developed.  The  optic  disc 
appeared,  by  daylight,  a  bright  yellowish  green,  sharply  defined, 
and  from  its  surface  and  the  surrounding  retina  had  disappeared 
all  traces  of  the  original  clouding.  The  small  hemorrhage  disap- 
peared, the  arteries  were  somewhat  contracted,  the  veins  remained 
of  normal  width.  In  another  case,  which  did  not  lead  to  blindness, 
but  which  reduced  vision  to  about  |,  with  contraction  of  the  visual 
field,  there  was  from  the  beginning  a  very  evident  neuritis.  In 
one  eye  it  was  only  partial,  and  limited  to  the  upper  half  of  the 
optic  nerve,  and,  corresponding  to  this,  the  defect  in  {he  visual  field 
was  below. 

The  relation  between  the  loss  of  blood  and  the  disease  of  the 
optic  nerve  is  wholly  unexplained.  It  cannot  be  due  to  simple 
anaemia,  since  not  only  does  copious  loss  of  blood  occur  without 
causing  atrophy  of  the  optic  nerve,  and  even  after  hsematemesis 
this  sad  complication  is  rare,  but  anaemia  did  not  exist  among  any 
of  those  who  were  blinded  under  these  circumstances. f 

Amauroses  due  to  orbital  causes,  such  as  tumors,  periostitis, 
inflammation  of  the  connective  tissue,  fractures  of  the  bony  orbital 
walls,  etc.,  may  be  caused  by  compression  of  the  nerve  or  by  retro- 
ocular  or  ophthalmoscopically  visible  neuritis. 

Certain  cases  in  which  a  slight  contusion  or  compression  of  the 
eye  has  immediately  caused  great  disturbance  of  vision  with  or 
without  defect  in  the  visual  field,  or  even  complete  blindness, 
remain  wholly  unexplained.     The  objective  appearance  in  such 

*  Arch,  f.  Ophth.,  B.  xii.  2,  pag.  149. 

t  Yon  Graefe,  Arch.  f.  Ophth.,  B.  vii.  1,  pag.  150. 


AMAUROSIS   SIMULATA.  546 

cases  is  at  first  wholly  negative.     Later,  atrophic  degeneration  of 
the  optic  nerve  may  develop.* 

The  occurrence  of  reflex  amauroses  is  also  asserted,  and  is 
referred  to  the  irritation  of  dental  nerves  in  carious  teeth. f  Ac- 
cording to  Hutchinson,!  these  reflex  effects  may  occur  when  the 
carious  teeth  are  not  painful. 

The  hypodermic  injection  of  strychnine  in  all  forms  of  ambly- 
opia has  lately  been  recommended. §  I  have  seen  a  number  of 
cases  improve  under  this  treatment,  just  as  might  happen  with 
any  treatment,  or  without  any  treatment  whatever ;  but  the  ma- 
jority of  the  absolutely  negative  results  is  so  great  that  I  have 
not  been  able  to  satisfy  myself  of  the  action  of  strychnine  upon 
the  optic  nerve.  I  have  never  seen  such  immediate  improvement 
of  vision  after  the  injection  of  strychnine  as  is  asserted  by  Nagel 
to  occur. 

Here  is  the  place  to  discuss  the  methods  for  detecting  simulated 
amblyopia.  If,  as  is  generally  the  case,  absolute  amaurosis  on  one 
side  be  simulated,  the  best  and  shortest  method  is  that  proposed  by 
Von  Graefe.ll  Only  the  healthy  eye  is  experimented  with,  and  a 
prism  of  from  6°  to  12°,  with  its  base  turned  upward  or  down- 
ward, is  placed  before  it.  If  now  a  candle  flame  or  a  dot  or  fine 
line  upon  a  white  paper  be  seen  double,  the  simulation  is  at  once 
proved,  and  at  the  same  time  the  degree  of  vision  in  the  pretended 
blind  eye  can  be  determined  with  sufficient  exactness.  As  a  fur- 
ther confirmation,  it  may  be  tried  whether  the  double  image  moves 
during  rotation  of  the  prism,  or  whether  the  diplopia  disappears 
upon  the  re-establishment  of  binocular  single  vision  when  the 
base  of  the  prism  is  turned  outward. 

It  sometimes  happens  that  the  simulators  deny  the  diplopia, 


*  Testelin,  Klin.  Monatsbl.,  1865,  pag.  358. 

t  Wecker,  Klin.  Monatsbl.,  1865,  pag.  269  ;  Alexander,  ibid.,  1868,  pag.  42. 

X  Oplith.  Hosp.  Kep.,  iv.  4,  pag.  381. 

§  Fremineau,  Gaz.  des  Hop.,  49,  1863;  Siimann,  Deutsche  Klinik,  1864, 
No.  44  und  45;  Talko,  Klin.  Monatsbl.  f.  Augenheilk.,  1868,  pag.  79,  und 
1869,  pag.  145;  Nagel,  Die  Behandlung  der  Amaurosen  mit  Strychnin, 
Tubingen,  1871. 

II  Arch.  f.  Ophth.,  B.  ii.  1,  pag.  266. 


546  AMAUROSIS   SIMULATA. 

because  they  happen  to  know  that  one  of  the  images  belongs  to 
the  pretended  blind  eye.  For  such  cases  Von  Graefe*  has  pro- 
posed a  modification  of  his  other  method.  The  pretended  blind 
eye  is  covered,  and  a  prism  refracting  vertically  is  so  held  before 
the  normal  eye  that  its  refracting  angle  bisects  the  pupillary  space. 
If  this  angle  be  sharp  enough,  and  the  pupil  be  not  too  small, 
monocular  diplopia  will  be  produced.  If  now  the  simulator  deny 
the  existence  of  the  monocular  diplopia,  there  is  good  ground  to 
doubt  the  truth  of  his  statements.  If,  however,  the  monocular 
diplopia  be  admitted,  it  can  be  very  easily  converted  into  binocular 
diplopia  by  uncovering  the  pretended  blind  eye  and  so  moving  the 
prism  that  it  shall  cover  the  entire  pupillary  region. 

The  stereoscope,  too,  may  be  employed  for  the  diagnosis  of 
simulated  blindness.  Each  eye  is  known  to  have  its  own  visual 
field.  Both  visual  fields  are  united  in  a  common  one,  and  it  is 
impossible  for  one  to  tell  the  part  performed  by  each  eye  separately 
in  this  common  visual  field.  Having  now  observed  that  a  union  of 
the  two  visual  fields  actually  takes  place,  we  can  present  an  object 
to  one  eye  which  appears  in  the  common  visual  field  without  the 
patient's  knowing  with  which  eye  he  sees  it.  There  is  no  diffi- 
culty in  thus  leading  his  judgment  astray.  If  union  of  the  visual 
fields  take  place,  an  object,  for  instance,  in  the  right  half  of  the 
left  visual  field,  lies  upon  the  right  side  in  the  common  visual 
field,  thus  conveying  the  impression  that  it  is  seen  with  the  right 
eye,  while  in  fact  the  retinal  image  belongs  only  to  the  left  eye. 

Under  certain  circumstances  Hering's  dropping  experiment 
(p.  113)  is  also  applicable  for  this  purpose. 

Where  there  is  simulation  of  unilateral  amblyopia,  an  exact 
determination  of  the  acuity  of  vision  at  different  distances  easily 
exposes  the  falsity  of  the  statements.  Simulated  defects  in  the 
visual  field  may  be  best  detected  by  repeatedly  sketching  the 
visual  field  at  different  distances  ;  or,  where  the  boundaries  of  the 
defect  in  any  direction  lie  near  the  fixation-point,  the  retinal 
image  may  be  thrown  by  a  prism  upon  the  pretended  non- 
sensitive  portion  of  the  retina,  and  its  functional  activity  proved 
by  the  diplopia  provoked  in  this  way.f 

*  Klin.  Monatsbl.,  1867,  pag.  53. 

t  Alfred  Graefe,  Arch.  f.  Ophth.,  B.  v.  1,  pag.  124. 


INDEX. 


A. 

Abscess  in  cornea,  301,  304. 

in  lids,  226. 

in  orbit,  192. 
Accommodation,  16,  21. 

anomalies  of,  11. 

changes  during,  21. 

formula  for,  25. 

latent,  47,  57. 

mechanism  of,  23. 

paralysis  of,  76. 

by  atropine,  61. 

phosphenes,  22. 

range  of,  16,  28. 

relative  range,  16. 

spasm  of,  83. 

with  aphakia,  391. 
Acuity  of  vision,  how  determined,  28. 
Albinismus,  416. 

Albuminuria  a  cause  of  retinitis,  465. 
Amaurosis,  526. 

after  hsematemesis,  543. 

from  intracranial  causes,  542. 

partialis  fugax,  541. 

simulata,  545. 

ursemic,  542. 
Amaurotic  cat's  eye,  496. 
Amblyopia,  526. 

congenita,  528. 

ex  anopsia,  528. 

from  lead  poison,  535. 

potatoria,  535. 
Anaesthesia  retinse,  532. 
Anchyloblepharon,  247. 
Anerythropsia,  529. 
Aneurism  of  arteries,  199. 
Angle  oc,  122. 
Angle  a',  42,  123. 


Angle  of  vision,  102. 
Anisometropia,  74. 
Annular  adhesions,  336. 
Aortic  insufficiency,  412. 
Aphakia,  60,  390. 

and  accommodation,  391. 
Apparent  myopia,  83. 
Apparent  strabismus  divergens,  125. 
Arcus  senilis,  325. 
Arteria  hyaloidea  persistens,  399. 
Arterial  pulsation,  410. 
Artificial  leech,  51,  52,  430. 
Asthenopia,  accommodative,  57,  62. 

astigmatic,  66. 

conjunctival,  62,  253. 

muscular,  168. 

nervous,  62,  86. 

spasm  of  accommodation,  83. 
Astigmatism,  63. 

after  cataract  operation,  391. 

compound,  69. 

correction  of,  70. 

irregular,  64,  312. 

mixed,  69. 

ophthalmoscopic  diagnosis,  118. 

regular,  64. 

simple,  69. 

test  objects,  68. 
Atheroma  of  retinal  arteries,  458. 
Atrophy  of  choroid,  35. 

of  eye,  341,  514. 

of  optic  nerve,  491,  538. 
Atropine  conjunctivitis,  257. 

B. 

Basedow's  disease,  195. 
Bicylindrical  lenses,  90. 
Bifocal  lenses,  90. 

547 


548 


INDEX. 


Bleeding  by  artificial  leech,  430. 
Blennorrhcea : 

conjunctival,  258. 

gonorrhceal,  262. 

neonatorum,  261. 

of  lachrymal  sac,  209. 
Blepharitis,  218. 
Blepharophimosis,  2-39. 
Blepharoplastic  operations,  247. 
Blepharospasm,  228. 
Blepharospath,  242. 
Blindness  in  epilepsy,  543. 

from  compression  of  nerve,  544. 

in  scarlatina,  543. 

in  typhoid  fever,  543. 

simulated,  545. 
Blue  spectacles,  28. 
Bougies  of  laminaria,  215. 
Bowman's  probes,  210.  212. 
Brain  disease,  neuro-retinitis,  480. 
Bright's  disease  and  retinitis,  462. 
Buphthalmus,  329. 
Burns  on  conjunctiva,  285. 


Calabar  bean,  80,  163,  319. 
Calcification  of  choroid,  428. 

of  lens,  338,  369. 
Camera  obscura,  12. 
Canaliculi  lacrymales,   occlusion   of, 

206. 
Cancroid  of  cornea,  325. 
Capillary  pulsation    in   optic   nerve, 

412. 
Capsule  of  Tenon,  193. 
Caries  of  orbit,  193. 
Caruncle,     lachrymal,    hypertrophy 

and  extirpation  of,  213. 
Cataract,  356. 

anterior  central,  366. 

black,  360. 

capsular,  385. 

complicated,  360. 

congenital,  360. 

cortical,  357. 

diabetic,  361. 

incipient,  363. 


Cataract,  lamellar,  364. 

Morgagnian,  358. 

nuclear,  358. 

operation  for,  370. 

posterior  polar,  44,  369. 

punctated,  363. 

pyramidal,  367. 

secondary,  387. 

senile,  359. 

striated,  363. 

traumatic,  361,  384. 
Caustics  in  blennorrhcea,  264,  274. 
Centre  of  rotation  of  eye,  126. 
Chalazion,  222. 
Changes  during  accommodation,  21. 

senile,  in  lens,  25. 
Chemosis,  259. 
Choked  disc,  478. 
Cholera  and  blindness,  489. 
Cholesterin  in  vitreous,  397. 
Choroid  appearance,  415. 

atrophy,  35. 

coloboma,  437. 

detachment,  431. 

embolism,  421. 

hemorrhages  in,  433. 

hyperaemia,  418. 

intervascular  spaces,  416. 

ossification,  347,  424. 

pigment  epithelium,  415. 

rupture,  433. 

sarcoma,  435. 

tubercle,  434. 

tumors,  435. 
Choroiditis,  420. 

acute,  424. 

disseminata,  426. 

due  to  embolism,  421. 

in  meningitis,  423. 

in  myopia,  44. 

in  recurrent  fever,  419. 

puerperal,  421. 

purulent,  420. 

syphilitic,  429. 
Chromhidrosis,  228. 
Ciliary  nerves,  neuralgia  of,  510 

paralysis  of,  511. 
Coloboma  of  choroid,  437. 


INDEX. 


549 


Coloboma  of  iris,  86,  353. 

of  lid,  244. 
Color-blindness,  529. 
Concomitant  squint,  149. 
Condylomata  iridis,  340. 
Conjugate  foci,  13. 
Conjunctiva,  burns,  285. 

foreign  bodies,  285. 

hypersemia  of,  252. 

tumors  of,  288. 
Conjunctivitis,  atropine,  257. 

blennorrhoeal,  258. 

diphtheritic,  268. 

follicular,  271. 

granular,  266. 

inoculated,  280,  282. 

phlyctenular,  289. 

simple,  254. 

trachomatous,  275. 
Corelysis,  839. 
Cornea,  abscess  in,  301,  304. 

cicatrices,  294. 

curvatures,  69,  121. 

facets,  295. 

fistula,  318. 

foreign  bodies,  321. 

opacities,  311. 

staphyloma,  315. 

tumors,  324. 

ulcers,  197,  260,  308. 

vesicles  on,  319. 

wounds,  321. 
Crossed  images,  183. 
Cryptogams  in  canaliculi,  206. 
Cyclitis,  418. 
Cylindrical  lenses,  69,  90. 
Cysticercus,  399. 
Cystoid  cicatrization,  521. 
Cysts  on  iris,  354. 

on  lids,  221,  227. 

D. 

Dacryoadenitis,  208. 
Dacryocystitis,  208. 
Dacryops,  205. 

Decussation  of  optic  nerve,  539. 
Dermoid  of  cornea,  324. 


Diabetes  and  cataract,  361. 
Different  refraction  in  e3'es,  74. 
Diphtheritis  conjunctivte,  268. 

and  paralysis,  81. 
Diplopia,  126,  130,  132. 

masked,  138. 

monocular,  86. 
Discision,  370,  371,  382. 
Distichiasis  congenita,  244. 

shrinkage  of  conjunctiva,  239. 
Divergence  of  visual  axes,  128. 
Double  images,  test,  136. 
Double  masked  images,  138. 
Dropping  experiment,  75,  113. 
Dynamic  squint,  169. 

E. 

Ectropion,  219,  233. 
Eczema  of  lids,  226. 
Elasticity  of  muscles,  155. 
Electricity,  82. 

Embolism  of  central  retinal  artery, 
487;  of  its  branches,  422. 

of  choroid,  421. 
Emmetropia,  12,  15. 
Emphysema  of  lids,  208. 

of  orbit,  201. 
Encephalitis      interstitialis,    corneal 

ulcer,  307. 
Entropion,  236. 
Enucleation,  348-352. 
Ephidrosis,  228. 
Epicanthus,  244. 
Epiphora,  210. 
Episcleritis,  326. 
Epithelioma  of  lids,  227. 
Ergotism  and  cataract,  361. 
Erysipelas,  191,  226. 
Examination,  range  of  accommoda- 
tion, 23. 

acuity  of  vision,  28. 

in  inverted  image,  100. 

in  upright  image,  96. 
Excavation  of  optic  nerve,  atrophic, 
492. 

glaucomatous,  502. 

physiological,  406,  506. 


550 


INDEX. 


Exercise,  paralyzed  muscles,  141. 
Exophthalmometers,  202. 
Exophthalmus,     obstructed    circula- 
tion, 198. 

inflamed  orbital  tissues,  193. 

morbus  Basedowii,  195. 

paralytic,  142. 

pulsating,  198. 

venous  hyperaemia,  198. 
Exostoses  of  orbit,  201. 
Extirpation  of  eye,  348,  352. 

of  lachrymal  gland,  206. 

of  lachrymal  sac,  215. 

of  orbital  contents,  201. 
Extraction,  370. 

flap,  371. 

linear,  370. 

with  capsule,  381. 
Extravasation  in  retina,  47,  463. 

P. 

Facets  of  cornea,  295. 
Facultative  hypermetropia,  53. 
Far  point,  15. 

Fatty  degeneration  of  muscles,  197. 
Febris  recurrens  and  choroiditis,  419. 
Field  of  vision  tested,  526. 
Fistula : 

lachrymal,  216. 

of  cornea,  318. 
Flimmerscotum,  541. 
Focal  illumination,  291. 

interval,  65. 

lines,  65. 
Follicles  of  conjunctiva,  271. 
Foreign  bodies  in  cornea,  321. 

in  anterior  chamber,  322. 

in  conjunctiva,  285. 

in  lens  and  vitreous,  385. 

in  orbit,  201. 
Formula  for  accommodation,  25. 

for  conjugate  foci,  14. 
Fovea  centralis,  414. 
Fracture  of  orbital  walls,  201. 
Fundus,  ophthalmoscopic  appearance, 

403. 
Fungus  haematodes,  495. 


Gerontoxon,  325. 
Glaucoma,  501. 

acutum,  514. 

chronicum,  513. 

fulminans,  514. 

hypermetropia  in,  515. 

inflammatory,  509. 

iridectomy  in,  517. 

malignum,  519. 

neuralgia  in,  516. 

secondary,  516. 

simplex,  502. 
Glioma  of  retina,  494. 
Glio-sarcoma,  495. 
Gonorrhoea!  blennorrhoea,  262. 
Granular  lids,  266. 
Granulations,  acute,  274. 
Gummata  iridis,  341. 

H. 

Habit,  force  of,  in  hypermetropia,  57. 
Heart    disease    and    retinal    hemor- 
rhage, 458. 
Hemeralopia,  188,  447,  529. 
Hemiopia,  539. 

homonymous,  540. 

temporal,  541. 
Hemorrhage    beneath     conjunctiva, 
284. 

in  choroid,  433. 

in  orbit,  201. 

in  retina,  47,  463. 

into  vitreous,  397. 
Hering's  experiment,  75,  113. 
Herpes  frontalis,  224. 
Homonymous  images,  133. 
Hordeolum,  221. 

Hyaline  membrane  thickened,  428. 
Hyalitis,  395. 
Hyaloid  artery,  399. 
Hydrocephalus  a  cause  of  blindness, 

481. 
Hydromeningitis,  342. 
Hydrophthalmus,  329. 
Hydrops  sacci  lacrymalis,  209. 


INDEX. 


551 


Hyperesthesia  of  retina,  534. 
Hypermetropia,  12,  52. 

absolute,  53, 

anatomical  condition,  59. 

and  strabismus  convergens,  149. 

congenital,  60. 

convex  lenses  in,  61. 

degree,  how  found,  57. 

facultative,  53. 

latent,  57,  61. 

manifest,  57. 

relative,  53. 
Hypopion,  295. 
Hypopion-keratitis,  295,  301. 
Hysteria,  231. 

I. 

Ice  in  blennorrhcea,  263. 
Illaqueatio,  244. 
Image,  ophthalmoscopic,  101. 
Incongruence  of  retinse,  157. 
Infiltration  of  cornea,  279. 
Innervation  of  ocular  muscles,  129. 
Inoculation,  gonorrhoeal,  282. 
Insufficiency  of  ocular   muscles,  51, 

169. 
Intervascular  spaces,  416. 
Intraocular  pressure,  410,  501,  507. 
Intraocular  tumors,  329,  435,  494. 
Inverted  image,  100. 
Iridalgia,  339. 

Iridectomy   in    cataract    operations, 
374. 

in  cloudiness  of  cornea,  313. 

in  discision,  383. 

in  glaucoma,  517. 

in  irido-cyclitis,  349. 

in  iritis  and  irido-choroiditis,  338. 

in  lamellar  cataract,  366. 

in  luxation  of  lens,  390. 

in  suppuration  of  cornea,  305. 

theory  of,  521. 
Irideremia,  353. 
Irido-choroiditis,  324,  336,  423. 
Irido-cyclitis,  344. 
Iridodesis,  321. 
Iridodialysis,  523. 


Iridotomy,  314. 

Iris,  innervation  of,  543. 

Iritis,  332. 

chronic,  336. 

gummosa,  341. 

idiopathic,  332. 

relapsing,  334. 

rheumatic,  334. 

secondary,  343. 

serosa,  342. 

syphilitic,  340. 

variolosa,  341. 

with  febris  recurrens,  341. 

with  gonorrhcea,  342. 

with  pannus  trachoma,  279. 
Irritation  in  myopia,  44. 
Ischemia  retinse,  482. 

K. 

Keratitis : 

fascicular,  293. 

hypopion,  295,  301. 

interstitial,  297. 

marginal,  289. 

neuro-paralytic,  306. 

parenchymatous,  297. 

phlyctenular,  292. 

profunda,  297. 

punctated,  299. 

purulent,  300. 

relapsing,  323. 

syphilitica,  298,  300. 

variolosa,  306. 

with  interstitial  encephalitis,  307. 
Keratoconus,  319. 


Lachrymal  canals,  obliteration,  207. 
Lachrymal  fistula,  216. 
Lachrymal  gland,  extirpation,  206. 

inflammation,  203. 
Lachrymal  sac,  inflammation,  208. 

obliteration,  215. 
Lagophthalmus,  233. 
Lamina  cribrosa,  404. 
Laminaria  bougies,  215. 
Latent  range  of  accommodation,  57. 


552 


INDEX. 


Leech,  artificial,  51,  52,  430. 
Lens,  calcification,  338,  369. 

changes  in  accommodation,  21. 

luxation,  388,  430. 

opacities  of,  356. 

neutralizing,  52. 

senile  changes,  26. 

Stokes',  73. 
Lenses,  bifocal,  90. 

cylindrical,  90. 

properties  of,  12,  87. 
Leptothrix,  206. 
Leucasmia,  462. 
Lice,  221 

Lids,  diseases  of.  218. 
Linear  extraction,  370. 
Liquefaction  of  vitreous,  893. 
Lithiasis  conjunctivie,  222. 
Lupus  of  lids,  227. 
Lymph  spaces,  191,  423,  481. 

M. 

Macropia,  85. 

Macula  lutea,  405,  413. 

diseased  in  myopia,  45. 

physiological  behavior,  414. 

retinitis  of  macula  lutea,  463, 469, 
Malignant  pustule  on  lid  ,  226. 
Mariotte's  blind  spot,  45. 
Masked  double  vision,  138. 
Medullary  sheaths,  retina,  439. 
Meibomian  glands,  219,  222. 
Melanoma  of  cornea,  325. 
Membrana     pupillaris     perseverans, 

353. 
Meningitis,  irido-choroiditis,  423. 
Meridian,  principal,  64. 
Meridional  asymmetry,  64,  117. 
Metamorphopsia,  46,  443,  462. 
Micropia,  77,  461. 
Miners'  nystagmus,  188. 
Moon-blindness,  531. 
Mouches  volantes,  44,  393. 
Movements  of  eyes,  126. 

in  myopia,  43,  51,  167. 
Muscles,  fatty  degeneration,  197. 

innervation  of  ocular,  129. 


Mydriasis,  77,  78. 
Myodesopia,  44,  393. 
Myopia,  12,  31. 

anatomical  changes,  32. 

apparent,  83. 

causes  of,  39. 

complications  in,  41,  153. 

irritation  in,  44. 

ophthalmoscopic  appearances,  35. 

spectacles  indicated,  48. 

spectacles  contra-indicated,  49. 

treatment,  47. 
Myosis,  84,  86. 

N. 

Narcosis  during  extraction,  380. 
Nasal  duct : 

probing,  210. 

stricture,  208. 
Near  point,  15,  16. 

absolute,  16. 

binocular,  16. 
Negative,  relative   range  of  accom- 
modation, 19. 
Nerve-sheaths,  medul.  of  ret.,  439. 
Nerve-sheaths,  separation  of,  34. 
Neuritis  and  neuro-retinitis,  475. 

descendens,  485. 

fulminans,  477. 

interstitialis,  484. 

retrobulbar,  193,  482. 

with  orbital  inflammation,  193. 
Nystagmus,  187,  454. 


(Edema  conjunctiva  sclerse,  284. 

retinae,  425. 
Onyx,  300. 

Ophthalmia  militaris,  283. 
Ophthalmometer,  119. 
Ophthalmoscope,  95. 

binocular,  111. 
Ophthalmoscopic  diagnosis  of  refrac- 
tion, 116. 

examination  by  daylight,  115. 

image,  size  of,  101. 


INDEX. 


553 


Optic  disc,  appearance,  403. 

excavation,  404. 

in  myopia,  37. 
Optic  nerve,  atrophy,  491. 

decussation,  539. 

distribution  of  iibres,  405. 

excavation,  404. 

inflammation  of,  475. 

ophthalmoscopic  appearance,  403. 
Optometer,  67. 
Orbit,  affections  of,  191. 
Orthopedic  treatment  of  strabismus, 

180. 
Ossification  of  choroid,  347,  424. 

of  vitreous,  395. 


Pannus  phlyctienulosus,  294. 
Pannus  trachomatosus,  276,  294. 
Panophthalmitis,  420,  422. 
Paracentesis  of  cornea,  299,  310. 
,        with  abscess,  306. 

with  ischsemia  retinfe,  483. 

with  ulcer,  309. 
Parallax,  binocular,  66. 

ophthalmoscopic,  408,  505. 
Paralysis  of  accommodation,  76. 

causes  of,  139. 

diphtheritic,  81. 

of  abducens,  134, 

of  ocular  muscles,  134,  197. 

of  oculo-motorius,  141. 

of  orbicularis,  232. 

of  trochlearis,  145. 

rheumatic,  139. 

syphilitic,  139. 
Pediculi,  221. 

Pemphigus  of  conjunctiva,  285. 
Perimeter,  528. 
Perineuritis,  484. 

Periosteal  extirpation  of  orbital  con- 
tents, 201. 
Periotomy.  297. 
Peripheral  linear  incision,  375. 
Periscopic  glasses,  89. 
Perivascular  neuritis,  474. 
Phlycttenulse  conjunctivas,  289. 

cornese,  292. 


Phosphenes,  22. 

Photophobia,     syn.     blepharospasm, 

228,  292. 
Phthisis  bulbi,  524. 
Pigmentation  of  disc,  493. 
Pigmentation  of  retina,  447. 
Pinguecula,  288. 
Polyopia,  monocular,  86. 
Polypi,  nasal,  213. 

of  lachrymal  sac,  217. 

of  nasal  duct,  217. 
Positive  relative  range  of  accommo- 
dation, 19. 
Presbyopia,  25. 

correct  by  lenses,  28. 
Principal  focus,  12. 
Principal  meridian,  64. 
Prisms,  91. 

in  diplopia,  140. 

in  strabismus,  172. 

overcoming,  131,  172. 
Probes,  Bowman's,  210,  212. 
Probing  nasal  duct,  210. 
Projection,  false,  in  paralysis  of  ocular 

muscles,  143. 
Prolapsus  iridis,  309. 
Protective  spectacles,  94. 
Pterygium,  285. 

cicatricial,  287. 
Ptosis,  143,  231. 
Pulsating  exophthalmus,  198. 
Pulsation  in  retina : 

arterial,  410,  506,  512. 

venous,  409. 
Puncta  lacrymalia,  anomalies,  206. 
Pupil,  occlusion,  335. 
Pupillary  membrane,  353. 
Purpura  hjemorrhagica,  458. 
Pustule,  malignant,  on  lid,  226. 

R. 

Kange  of  accommodation,  16. 

determining,  23. 
Reclination,  370. 
Reflex  from  retina,  412. 
Refraction,  anomalies  of,  11. 

difterent  in  two  eyes,  74. 

ophthalmoscopic  diagnosis,  116. 


36 


554 


INDEX. 


Kelative  range  of  accommodation,  16. 

in  myopia,  42. 
Retina,  cystoid  bodies  in,  446. 

detachment,  47,  441,  515,  517. 

embolism,  422. 

hemorrhage  in,  455. 

hypersemia,  440. 

inflammation,  459. 

medullary  sheaths,  4-39. 

cedema  of,  425,  445. 

opacity  of,  412. 

pigmentation  of,  447. 

reflex  from,  413. 

rupture  of,  443. 

vessels  of,  409,  489. 
Ketinal  image  suppressed,  43,  157. 
Retinitis,  459. 

albuminurica,  465. 

anatomical  changes,  470. 

hemorrhagica,  463. 

leucsemica,  467. 

nyctalopica,  468. 

of  Bright's  disease,  470. 

of  macula  lutea,  469. 

pigmentosa,  447. 

septica,  462. 

syphilitica,  463. 
Retrobulbar  neuritis,  193,  482. 
Rheumatic  paralysis,  139. 


Sarcoma  of  choroid,  435. 
School  furniture,  40,  48. 
Sclera,  rupture,  390. 
Scleral  stripe,  119. 
Scleritis,  326. 
Sclerotico-choroiditis,  41. 
Scorbutus  and  hemeralopia,  -531. 
Scotoma,  46,  535. 
Scrofula  and  keratitis,  294. 
Seborrhoea,  228. 
Snellen's  types,  28. 
Snow-blindness,  531. 
Spasm  : 

of  accommodation,  52. 

of  ocular  muscles,  148. 
Spectacles,  28,  87. 


Spectacles,  bifocal,  90. 

blue,  28. 

protective,  94. 
Spherical  lenses,  87. 
Spinal  disease  and  blindness,  538. 
Squinting  angle,  154. 
Staphyloma  cornese,  309,  315. 

posticum,  33,  46,  328. 

sclera,  328. 
Staphylomatous  cicatrices,  309. 
Stauungspapille,  478. 
Stenopaic  apparatus,  69,  94,  313. 
Stereoscope    in    amaurosis    simulata, 
646. 

in  strabismus,  159. 
Stereoscopic  image,  113. 
Stokes'  lens,  73. 
Strabismus,  149. 

apparent,  125. 

causes  of,  150. 

convergens,  149. 

convergens  alternans,  1-54. 

convergens,  periodic,  155. 

divergens,  76,  165. 

divergens  alternans,  75. 

divergens,  relative,  76. 

dynamic,  169. 

operation  for,  144,  174. 

paralytic,  138,  153. 

upward  or  downward,  173. 
Strabometer,  156. 
Stricture  of  nasal  duc-t,  208. 
Strychnine  in  amaurosis,  .545. 
Stye,  221. 

Style  for  nasal  duct,  215. 
Suppression  of  retinal  images,  43,  157. 
Symblepharon,  244,  285. 
Symmetry  of  retinae,  157. 
Sympathetic  affections,  230,  845. 
Syndectomy,  297. 
Synechiaa,  anterior,  309. 

posterior,  333.  • 


Tarsal  glands,  219,  222. 
Tarsorraphy,  235. 
Telangiectasia  of  lids,  227. 
Temporal  hemiopic  defects,  541. 


INDEX. 


555 


Tenon's  capsule,  inflammation  of,  193. 
Tenotomy,  61,  144,  174. 
Tension,  intraocular,  507. 
Test  letters,  28. 

lines,  astigmatism,  68. 
Testing  vision,  362. 
Thrombus  of  vena  ophthalmica,  199. 
Tonometer,  507. 
Torpor  retinas,  447,  529. 
Trachoma,  267,  275. 
Transplanted  skin,  249. 
Trichiasis,  239,  278. 
Tubercle  in  chiasm,  539. 
Tumors,  conjunctival,  288. 

corneal,  324. 

gummy,  340. 

intraocular,  329,  435,  494. 

intraorbital,  199,  412. 

of  iris,  353. 

u. 

Ulcers  of  cornea,  197,  260,  308. 

of  lids,  218,  227. 
Ulcus  corneae  serpens,  302. 
Unguis,  300. 
Upright  image,  96. 
Urajmic  amaurosis,  467. 


Varicosity  of  orbital  veins,  199. 
Vascularization  of  cornea,  297. 


Vesicles  of  cornea,  319. 
Vesicular  granulations,  272. 
Virtual  image,  15. 
Vision,  acuity  of,  28. 

angle  of,  102. 

empirical  theory,  158,  188. 

line  of,  42. 

testing,  28,  362. 
Visual  field,  526. 
Visual-field  amblyopia,  534. 
Vitiligoidea  of  lids,  228. 
Vitreous,  detachment,  393. 

hemorrhage  into,  397. 

liquefaction,  393. 

opacity,  394. 

ossification,  395. 

vascularization,  398. 

w. 

"Weber's  knife,  207. 
Wecker's  scissors,  314. 
Wounds  of  cornea,  321. 

X. 

Xanthelasma  of  lids,  228. 
Xerosis,  278,  308. 

z.     • 

Zoster  ophthalmicus,  224. 


EEEATA. 

Page  78,  line  10,  for  "  myopia"  read  "  micropia." 

Page  78,  line  3  of  the  foot-note,  for  "physical"  read  "  psychical 

Page  137,  line  32,  for^"  early"  read  "  clearly." 

Page  156,  line  12,  for  "  lachry mails"  read  "  lacrymale." 

Page  269,  line  1,  for  "  lachrymal"  read  "  nasal." 

Page  318,  line  19,  for  "  in"  read  "  into." 

Page  477,  line  15,  for  "194"  read  "  199." 


WW 

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